From 328b08511256e0761167a133ae5d2b8b2c2ddb0d Mon Sep 17 00:00:00 2001 From: vector Date: Thu, 27 Sep 2018 19:49:47 +0800 Subject: [PATCH 01/14] 'update' --- pom.xml | 4 +- .../chap10/OperationsWithOptional.java | 50 ++--- .../lambdasinaction/chap10/OptionalMain.java | 48 ++-- .../chap2/FilteringApples.java | 15 +- .../chap6/CollectorHarness.java | 46 ++-- .../java/lambdasinaction/chap6/Grouping.java | 192 ++++++++-------- .../chap6/PartitionPrimeNumbers.java | 212 +++++++++--------- 7 files changed, 290 insertions(+), 277 deletions(-) diff --git a/pom.xml b/pom.xml index 10e5035e..37cbf712 100644 --- a/pom.xml +++ b/pom.xml @@ -37,8 +37,8 @@ maven-compiler-plugin 3.1 - 1.9 - 1.9 + 1.8 + 1.8 diff --git a/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java b/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java index d2940969..42651b46 100644 --- a/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java +++ b/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java @@ -1,25 +1,25 @@ -package lambdasinaction.chap10; - -import java.util.*; - -import static java.util.Optional.of; -import static java.util.Optional.empty; - -public class OperationsWithOptional { - - public static void main(String... args) { - System.out.println(max(of(3), of(5))); - System.out.println(max(empty(), of(5))); - - Optional opt1 = of(5); - Optional opt2 = opt1.or(() -> of(4)); - - System.out.println( - of(5).or(() -> of(4)) - ); - } - - public static final Optional max(Optional i, Optional j) { - return i.flatMap(a -> j.map(b -> Math.max(a, b))); - } -} +//package lambdasinaction.chap10; +// +//import java.util.*; +// +//import static java.util.Optional.of; +//import static java.util.Optional.empty; +// +//public class OperationsWithOptional { +// +// public static void main(String... args) { +// System.out.println(max(of(3), of(5))); +// System.out.println(max(empty(), of(5))); +// +// Optional opt1 = of(5); +// Optional opt2 = opt1.or(() -> of(4)); +// +// System.out.println( +// of(5).or(() -> of(4)) +// ); +// } +// +// public static final Optional max(Optional i, Optional j) { +// return i.flatMap(a -> j.map(b -> Math.max(a, b))); +// } +//} diff --git a/src/main/java/lambdasinaction/chap10/OptionalMain.java b/src/main/java/lambdasinaction/chap10/OptionalMain.java index dcd97792..56d742eb 100644 --- a/src/main/java/lambdasinaction/chap10/OptionalMain.java +++ b/src/main/java/lambdasinaction/chap10/OptionalMain.java @@ -1,24 +1,24 @@ -package lambdasinaction.chap10; - -import java.util.*; - -import static java.util.stream.Collectors.toSet; - -public class OptionalMain { - - public String getCarInsuranceName(Optional person) { - return person.flatMap(Person::getCar) - .flatMap(Car::getInsurance) - .map(Insurance::getName) - .orElse("Unknown"); - } - - public Set getCarInsuranceNames(List persons) { - return persons.stream() - .map(Person::getCar) - .map(optCar -> optCar.flatMap(Car::getInsurance)) - .map(optInsurance -> optInsurance.map(Insurance::getName)) - .flatMap(Optional::stream) - .collect(toSet()); - } -} +//package lambdasinaction.chap10; +// +//import java.util.*; +// +//import static java.util.stream.Collectors.toSet; +// +//public class OptionalMain { +// +// public String getCarInsuranceName(Optional person) { +// return person.flatMap(Person::getCar) +// .flatMap(Car::getInsurance) +// .map(Insurance::getName) +// .orElse("Unknown"); +// } +// +// public Set getCarInsuranceNames(List persons) { +// return persons.stream() +// .map(Person::getCar) +// .map(optCar -> optCar.flatMap(Car::getInsurance)) +// .map(optInsurance -> optInsurance.map(Insurance::getName)) +// .flatMap(Optional::stream) +// .collect(toSet()); +// } +//} diff --git a/src/main/java/lambdasinaction/chap2/FilteringApples.java b/src/main/java/lambdasinaction/chap2/FilteringApples.java index 0f61fd08..7bd8288f 100644 --- a/src/main/java/lambdasinaction/chap2/FilteringApples.java +++ b/src/main/java/lambdasinaction/chap2/FilteringApples.java @@ -31,11 +31,24 @@ public static void main(String ... args){ // [Apple{color='red', weight=120}] List redApples2 = filter(inventory, new ApplePredicate() { public boolean test(Apple a){ - return a.getColor().equals("red"); + return a.getColor().equals("red"); } }); System.out.println(redApples2); + + List red = filter(inventory, (Apple a) -> a.getColor().equals("red")); + + inventory.sort(new Comparator() { + @Override + public int compare(Apple o1, Apple o2) { + return o1.getWeight().compareTo(o2.getWeight()); + } + }); + + inventory.sort(Comparator.comparing(Apple::getWeight)); + + } public static List filterGreenApples(List inventory){ diff --git a/src/main/java/lambdasinaction/chap6/CollectorHarness.java b/src/main/java/lambdasinaction/chap6/CollectorHarness.java index 8370be16..46bab3b0 100644 --- a/src/main/java/lambdasinaction/chap6/CollectorHarness.java +++ b/src/main/java/lambdasinaction/chap6/CollectorHarness.java @@ -1,23 +1,23 @@ -package lambdasinaction.chap6; - -import java.util.function.*; - -public class CollectorHarness { - - public static void main(String[] args) { - //System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimes) + " msecs"); - System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimesWithCustomCollector) + " msecs" ); - } - - private static long execute(Consumer primePartitioner) { - long fastest = Long.MAX_VALUE; - for (int i = 0; i < 10; i++) { - long start = System.nanoTime(); - primePartitioner.accept(1_000_000); - long duration = (System.nanoTime() - start) / 1_000_000; - if (duration < fastest) fastest = duration; - System.out.println("done in " + duration); - } - return fastest; - } -} +//package lambdasinaction.chap6; +// +//import java.util.function.*; +// +//public class CollectorHarness { +// +// public static void main(String[] args) { +// //System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimes) + " msecs"); +// System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimesWithCustomCollector) + " msecs" ); +// } +// +// private static long execute(Consumer primePartitioner) { +// long fastest = Long.MAX_VALUE; +// for (int i = 0; i < 10; i++) { +// long start = System.nanoTime(); +// primePartitioner.accept(1_000_000); +// long duration = (System.nanoTime() - start) / 1_000_000; +// if (duration < fastest) fastest = duration; +// System.out.println("done in " + duration); +// } +// return fastest; +// } +//} diff --git a/src/main/java/lambdasinaction/chap6/Grouping.java b/src/main/java/lambdasinaction/chap6/Grouping.java index 9105cc80..37aa39a4 100644 --- a/src/main/java/lambdasinaction/chap6/Grouping.java +++ b/src/main/java/lambdasinaction/chap6/Grouping.java @@ -1,96 +1,96 @@ -package lambdasinaction.chap6; - -import java.util.*; - -import static java.util.stream.Collectors.*; -import static lambdasinaction.chap6.Dish.dishTags; -import static lambdasinaction.chap6.Dish.menu; - -public class Grouping { - - enum CaloricLevel { DIET, NORMAL, FAT }; - - public static void main(String ... args) { - System.out.println("Dishes grouped by type: " + groupDishesByType()); - System.out.println("Dish names grouped by type: " + groupDishNamesByType()); - System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); - System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); - System.out.println("Dishes grouped by caloric level: " + groupDishesByCaloricLevel()); - System.out.println("Dishes grouped by type and caloric level: " + groupDishedByTypeAndCaloricLevel()); - System.out.println("Count dishes in groups: " + countDishesInGroups()); - System.out.println("Most caloric dishes by type: " + mostCaloricDishesByType()); - System.out.println("Most caloric dishes by type: " + mostCaloricDishesByTypeWithoutOprionals()); - System.out.println("Sum calories by type: " + sumCaloriesByType()); - System.out.println("Caloric levels by type: " + caloricLevelsByType()); - } - - private static Map> groupDishesByType() { - return menu.stream().collect(groupingBy(Dish::getType)); - } - - private static Map> groupDishNamesByType() { - return menu.stream().collect(groupingBy(Dish::getType, mapping(Dish::getName, toList()))); - } - - private static Map> groupDishTagsByType() { - return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); - } - - private static Map> groupCaloricDishesByType() { -// return menu.stream().filter(dish -> dish.getCalories() > 500).collect(groupingBy(Dish::getType)); - return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); - } - - private static Map> groupDishesByCaloricLevel() { - return menu.stream().collect( - groupingBy(dish -> { - if (dish.getCalories() <= 400) return CaloricLevel.DIET; - else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; - else return CaloricLevel.FAT; - } )); - } - - private static Map>> groupDishedByTypeAndCaloricLevel() { - return menu.stream().collect( - groupingBy(Dish::getType, - groupingBy((Dish dish) -> { - if (dish.getCalories() <= 400) return CaloricLevel.DIET; - else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; - else return CaloricLevel.FAT; - } ) - ) - ); - } - - private static Map countDishesInGroups() { - return menu.stream().collect(groupingBy(Dish::getType, counting())); - } - - private static Map> mostCaloricDishesByType() { - return menu.stream().collect( - groupingBy(Dish::getType, - reducing((Dish d1, Dish d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); - } - - private static Map mostCaloricDishesByTypeWithoutOprionals() { - return menu.stream().collect( - groupingBy(Dish::getType, - collectingAndThen( - reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2), - Optional::get))); - } - - private static Map sumCaloriesByType() { - return menu.stream().collect(groupingBy(Dish::getType, - summingInt(Dish::getCalories))); - } - - private static Map> caloricLevelsByType() { - return menu.stream().collect( - groupingBy(Dish::getType, mapping( - dish -> { if (dish.getCalories() <= 400) return CaloricLevel.DIET; - else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; - else return CaloricLevel.FAT; }, - toSet() ))); - } -} +//package lambdasinaction.chap6; +// +//import java.util.*; +// +//import static java.util.stream.Collectors.*; +//import static lambdasinaction.chap6.Dish.dishTags; +//import static lambdasinaction.chap6.Dish.menu; +// +//public class Grouping { +// +// enum CaloricLevel { DIET, NORMAL, FAT }; +// +// public static void main(String ... args) { +// System.out.println("Dishes grouped by type: " + groupDishesByType()); +// System.out.println("Dish names grouped by type: " + groupDishNamesByType()); +// System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); +// System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); +// System.out.println("Dishes grouped by caloric level: " + groupDishesByCaloricLevel()); +// System.out.println("Dishes grouped by type and caloric level: " + groupDishedByTypeAndCaloricLevel()); +// System.out.println("Count dishes in groups: " + countDishesInGroups()); +// System.out.println("Most caloric dishes by type: " + mostCaloricDishesByType()); +// System.out.println("Most caloric dishes by type: " + mostCaloricDishesByTypeWithoutOprionals()); +// System.out.println("Sum calories by type: " + sumCaloriesByType()); +// System.out.println("Caloric levels by type: " + caloricLevelsByType()); +// } +// +// private static Map> groupDishesByType() { +// return menu.stream().collect(groupingBy(Dish::getType)); +// } +// +// private static Map> groupDishNamesByType() { +// return menu.stream().collect(groupingBy(Dish::getType, mapping(Dish::getName, toList()))); +// } +// +// private static Map> groupDishTagsByType() { +// return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); +// } +// +// private static Map> groupCaloricDishesByType() { +//// return menu.stream().filter(dish -> dish.getCalories() > 500).collect(groupingBy(Dish::getType)); +// return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); +// } +// +// private static Map> groupDishesByCaloricLevel() { +// return menu.stream().collect( +// groupingBy(dish -> { +// if (dish.getCalories() <= 400) return CaloricLevel.DIET; +// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; +// else return CaloricLevel.FAT; +// } )); +// } +// +// private static Map>> groupDishedByTypeAndCaloricLevel() { +// return menu.stream().collect( +// groupingBy(Dish::getType, +// groupingBy((Dish dish) -> { +// if (dish.getCalories() <= 400) return CaloricLevel.DIET; +// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; +// else return CaloricLevel.FAT; +// } ) +// ) +// ); +// } +// +// private static Map countDishesInGroups() { +// return menu.stream().collect(groupingBy(Dish::getType, counting())); +// } +// +// private static Map> mostCaloricDishesByType() { +// return menu.stream().collect( +// groupingBy(Dish::getType, +// reducing((Dish d1, Dish d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); +// } +// +// private static Map mostCaloricDishesByTypeWithoutOprionals() { +// return menu.stream().collect( +// groupingBy(Dish::getType, +// collectingAndThen( +// reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2), +// Optional::get))); +// } +// +// private static Map sumCaloriesByType() { +// return menu.stream().collect(groupingBy(Dish::getType, +// summingInt(Dish::getCalories))); +// } +// +// private static Map> caloricLevelsByType() { +// return menu.stream().collect( +// groupingBy(Dish::getType, mapping( +// dish -> { if (dish.getCalories() <= 400) return CaloricLevel.DIET; +// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; +// else return CaloricLevel.FAT; }, +// toSet() ))); +// } +//} diff --git a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java index 69d7c4ca..04de7674 100644 --- a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java +++ b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java @@ -1,106 +1,106 @@ -package lambdasinaction.chap6; - -import java.util.*; -import java.util.function.*; -import java.util.stream.*; - -import static java.util.stream.Collectors.*; -import static java.util.stream.Collector.Characteristics.*; - -public class PartitionPrimeNumbers { - - public static void main(String ... args) { - System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimes(100)); - System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimesWithCustomCollector(100)); - - } - - public static Map> partitionPrimes(int n) { - return IntStream.rangeClosed(2, n).boxed() - .collect(partitioningBy(candidate -> isPrime(candidate))); - } - - public static boolean isPrime(int candidate) { - return IntStream.rangeClosed(2, candidate-1) - .limit((long) Math.floor(Math.sqrt((double) candidate)) - 1) - .noneMatch(i -> candidate % i == 0); - } - - public static Map> partitionPrimesWithCustomCollector(int n) { - return IntStream.rangeClosed(2, n).boxed().collect(new PrimeNumbersCollector()); - } - - public static boolean isPrime(List primes, Integer candidate) { - double candidateRoot = Math.sqrt((double) candidate); - //return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); - return primes.stream().takeWhile(i -> i <= candidateRoot).noneMatch(i -> candidate % i == 0); - } -/* - public static List takeWhile(List list, Predicate p) { - int i = 0; - for (A item : list) { - if (!p.test(item)) { - return list.subList(0, i); - } - i++; - } - return list; - } -*/ - public static class PrimeNumbersCollector - implements Collector>, Map>> { - - @Override - public Supplier>> supplier() { - return () -> new HashMap>() {{ - put(true, new ArrayList()); - put(false, new ArrayList()); - }}; - } - - @Override - public BiConsumer>, Integer> accumulator() { - return (Map> acc, Integer candidate) -> { - acc.get( isPrime( acc.get(true), - candidate) ) - .add(candidate); - }; - } - - @Override - public BinaryOperator>> combiner() { - return (Map> map1, Map> map2) -> { - map1.get(true).addAll(map2.get(true)); - map1.get(false).addAll(map2.get(false)); - return map1; - }; - } - - @Override - public Function>, Map>> finisher() { - return i -> i; - } - - @Override - public Set characteristics() { - return Collections.unmodifiableSet(EnumSet.of(IDENTITY_FINISH)); - } - } - - public Map> partitionPrimesWithInlineCollector(int n) { - return Stream.iterate(2, i -> i + 1).limit(n) - .collect( - () -> new HashMap>() {{ - put(true, new ArrayList()); - put(false, new ArrayList()); - }}, - (acc, candidate) -> { - acc.get( isPrime(acc.get(true), candidate) ) - .add(candidate); - }, - (map1, map2) -> { - map1.get(true).addAll(map2.get(true)); - map1.get(false).addAll(map2.get(false)); - }); - } -} +//package lambdasinaction.chap6; +// +//import java.util.*; +//import java.util.function.*; +//import java.util.stream.*; +// +//import static java.util.stream.Collectors.*; +//import static java.util.stream.Collector.Characteristics.*; +// +//public class PartitionPrimeNumbers { +// +// public static void main(String ... args) { +// System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimes(100)); +// System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimesWithCustomCollector(100)); +// +// } +// +// public static Map> partitionPrimes(int n) { +// return IntStream.rangeClosed(2, n).boxed() +// .collect(partitioningBy(candidate -> isPrime(candidate))); +// } +// +// public static boolean isPrime(int candidate) { +// return IntStream.rangeClosed(2, candidate-1) +// .limit((long) Math.floor(Math.sqrt((double) candidate)) - 1) +// .noneMatch(i -> candidate % i == 0); +// } +// +// public static Map> partitionPrimesWithCustomCollector(int n) { +// return IntStream.rangeClosed(2, n).boxed().collect(new PrimeNumbersCollector()); +// } +// +// public static boolean isPrime(List primes, Integer candidate) { +// double candidateRoot = Math.sqrt((double) candidate); +// //return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); +// return primes.stream().takeWhile(i -> i <= candidateRoot).noneMatch(i -> candidate % i == 0); +// } +///* +// public static List takeWhile(List list, Predicate p) { +// int i = 0; +// for (A item : list) { +// if (!p.test(item)) { +// return list.subList(0, i); +// } +// i++; +// } +// return list; +// } +//*/ +// public static class PrimeNumbersCollector +// implements Collector>, Map>> { +// +// @Override +// public Supplier>> supplier() { +// return () -> new HashMap>() {{ +// put(true, new ArrayList()); +// put(false, new ArrayList()); +// }}; +// } +// +// @Override +// public BiConsumer>, Integer> accumulator() { +// return (Map> acc, Integer candidate) -> { +// acc.get( isPrime( acc.get(true), +// candidate) ) +// .add(candidate); +// }; +// } +// +// @Override +// public BinaryOperator>> combiner() { +// return (Map> map1, Map> map2) -> { +// map1.get(true).addAll(map2.get(true)); +// map1.get(false).addAll(map2.get(false)); +// return map1; +// }; +// } +// +// @Override +// public Function>, Map>> finisher() { +// return i -> i; +// } +// +// @Override +// public Set characteristics() { +// return Collections.unmodifiableSet(EnumSet.of(IDENTITY_FINISH)); +// } +// } +// +// public Map> partitionPrimesWithInlineCollector(int n) { +// return Stream.iterate(2, i -> i + 1).limit(n) +// .collect( +// () -> new HashMap>() {{ +// put(true, new ArrayList()); +// put(false, new ArrayList()); +// }}, +// (acc, candidate) -> { +// acc.get( isPrime(acc.get(true), candidate) ) +// .add(candidate); +// }, +// (map1, map2) -> { +// map1.get(true).addAll(map2.get(true)); +// map1.get(false).addAll(map2.get(false)); +// }); +// } +//} From fff8cba6c670ba733dba811810624c1fc9442388 Mon Sep 17 00:00:00 2001 From: vector Date: Fri, 28 Sep 2018 20:24:21 +0800 Subject: [PATCH 02/14] 'update' --- .../java/lambdasinaction/chap3/Demo342.java | 22 ++++++++++++++ .../java/lambdasinaction/chap3/Demo343.java | 25 ++++++++++++++++ .../java/lambdasinaction/chap3/demo341.java | 30 +++++++++++++++++++ 3 files changed, 77 insertions(+) create mode 100644 src/main/java/lambdasinaction/chap3/Demo342.java create mode 100644 src/main/java/lambdasinaction/chap3/Demo343.java create mode 100644 src/main/java/lambdasinaction/chap3/demo341.java diff --git a/src/main/java/lambdasinaction/chap3/Demo342.java b/src/main/java/lambdasinaction/chap3/Demo342.java new file mode 100644 index 00000000..a17c6e85 --- /dev/null +++ b/src/main/java/lambdasinaction/chap3/Demo342.java @@ -0,0 +1,22 @@ +package lambdasinaction.chap3; + +import java.util.Arrays; +import java.util.List; +import java.util.function.Consumer; + +/** + * @author vector + * @date: 2018/9/28 0028 14:00 + */ +public class Demo342 { + public static void forEach(List list, Consumer consumer) { + for (T t : list) { + consumer.accept(t); + } + } + + public static void main(String[] args) { + + forEach(Arrays.asList(1,2,3,4,5,6),(Integer i)-> System.out.println(i)); + } +} diff --git a/src/main/java/lambdasinaction/chap3/Demo343.java b/src/main/java/lambdasinaction/chap3/Demo343.java new file mode 100644 index 00000000..3fd27779 --- /dev/null +++ b/src/main/java/lambdasinaction/chap3/Demo343.java @@ -0,0 +1,25 @@ +package lambdasinaction.chap3; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.function.Function; + +/** + * @author vector + * @date: 2018/9/28 0028 14:21 + */ +public class Demo343 { + public static List map(List list, Function function) { + List result = new ArrayList<>(); + for (T t : list) { + result.add(function.apply(t)); + } + return result; + } + + public static void main(String[] args) { + List map = map(Arrays.asList("ladf", "in", "action"), (String s) -> s.length()); + System.out.println(map); + } +} diff --git a/src/main/java/lambdasinaction/chap3/demo341.java b/src/main/java/lambdasinaction/chap3/demo341.java new file mode 100644 index 00000000..ea2c86ed --- /dev/null +++ b/src/main/java/lambdasinaction/chap3/demo341.java @@ -0,0 +1,30 @@ +package lambdasinaction.chap3; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.function.Predicate; + +/** + * @author vector + * @date: 2018/9/28 0028 13:51 + */ +public class demo341 { + public static List filter(List list, Predicate p) { + List result = new ArrayList<>(); + for (T t : list) { + if (p.test(t)) { + result.add(t); + } + } + return result; + } + + public static void main(String[] args) { + Predicate nonEmptyStringPredicate = (String s) -> !s.isEmpty(); + List filter = filter(Arrays.asList("123","","asv","^&*"), nonEmptyStringPredicate); + System.out.println(filter); + } + + +} From d258bb2b7f46a87234db2a39f6bf11093f07d590 Mon Sep 17 00:00:00 2001 From: vector Date: Sat, 29 Sep 2018 18:18:13 +0800 Subject: [PATCH 03/14] =?UTF-8?q?'=E5=AE=8C=E6=88=90=E7=AC=AC=E4=BA=94?= =?UTF-8?q?=E9=83=A8=E5=88=86'?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../lambdasinaction/chap4/StreamBasic.java | 15 ++++---- .../java/lambdasinaction/chap5/Demo522.java | 21 +++++++++++ .../java/lambdasinaction/chap5/Demo551.java | 36 +++++++++++++++++++ 3 files changed, 65 insertions(+), 7 deletions(-) create mode 100644 src/main/java/lambdasinaction/chap5/Demo522.java create mode 100644 src/main/java/lambdasinaction/chap5/Demo551.java diff --git a/src/main/java/lambdasinaction/chap4/StreamBasic.java b/src/main/java/lambdasinaction/chap4/StreamBasic.java index 19a8c176..ebfa074c 100644 --- a/src/main/java/lambdasinaction/chap4/StreamBasic.java +++ b/src/main/java/lambdasinaction/chap4/StreamBasic.java @@ -1,6 +1,7 @@ package lambdasinaction.chap4; import java.util.*; +import java.util.function.Function; import java.util.stream.*; import static java.util.Comparator.comparing; @@ -10,7 +11,7 @@ public class StreamBasic { - public static void main(String...args){ + public static void main(String... args) { // Java 7 getLowCaloricDishesNamesInJava7(Dish.menu).forEach(System.out::println); @@ -21,26 +22,26 @@ public static void main(String...args){ } - public static List getLowCaloricDishesNamesInJava7(List dishes){ + public static List getLowCaloricDishesNamesInJava7(List dishes) { List lowCaloricDishes = new ArrayList<>(); - for(Dish d: dishes){ - if(d.getCalories() < 400){ + for (Dish d : dishes) { + if (d.getCalories() < 400) { lowCaloricDishes.add(d); } } List lowCaloricDishesName = new ArrayList<>(); Collections.sort(lowCaloricDishes, new Comparator() { - public int compare(Dish d1, Dish d2){ + public int compare(Dish d1, Dish d2) { return Integer.compare(d1.getCalories(), d2.getCalories()); } }); - for(Dish d: lowCaloricDishes){ + for (Dish d : lowCaloricDishes) { lowCaloricDishesName.add(d.getName()); } return lowCaloricDishesName; } - public static List getLowCaloricDishesNamesInJava8(List dishes){ + public static List getLowCaloricDishesNamesInJava8(List dishes) { return dishes.stream() .filter(d -> d.getCalories() < 400) .sorted(comparing(Dish::getCalories)) diff --git a/src/main/java/lambdasinaction/chap5/Demo522.java b/src/main/java/lambdasinaction/chap5/Demo522.java new file mode 100644 index 00000000..348b8cc2 --- /dev/null +++ b/src/main/java/lambdasinaction/chap5/Demo522.java @@ -0,0 +1,21 @@ +package lambdasinaction.chap5; + +import java.util.Arrays; +import java.util.List; +import java.util.function.Function; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +import static java.util.stream.Collectors.toList; + +/** + * @author vector + * @date: 2018/9/29 0029 15:48 + */ +public class Demo522 { + public static void main(String[] args) { + List hw = Arrays.asList("Hello", "World"); + List collect = hw.stream().map(word -> word.split("")).flatMap(Arrays::stream).distinct().collect(toList()); + System.out.println(collect); + } +} diff --git a/src/main/java/lambdasinaction/chap5/Demo551.java b/src/main/java/lambdasinaction/chap5/Demo551.java new file mode 100644 index 00000000..8fa16d23 --- /dev/null +++ b/src/main/java/lambdasinaction/chap5/Demo551.java @@ -0,0 +1,36 @@ +package lambdasinaction.chap5; + +import java.util.*; +import java.util.stream.Collectors; + +import static java.util.Comparator.comparing; +import static java.util.stream.Collectors.joining; +import static java.util.stream.Collectors.toList; + +/** + * @author vector + * @date: 2018/9/29 0029 16:48 + */ +public class Demo551 { + public static void main(String[] args) { + List list = new ArrayList<>(); + List list1 = list.stream().filter(item -> item.getYear() == 2011).sorted(comparing(Transaction::getValue)).collect(toList()); + + Set set2 = list.stream().map(item -> item.getTrader().getCity()).collect(Collectors.toSet()); + + List list3 = list.stream().map(Transaction::getTrader).filter(item -> item.getCity().equals("剑桥")).distinct().sorted(comparing(Trader::getName)).collect(toList()); + + String collect4 = list.stream().map(item -> item.getTrader().getName()).distinct().sorted().collect(joining()); + + boolean boolean5 = list.stream().anyMatch(item -> item.getTrader().getCity().equals("米兰")); + + list.stream().filter(item->item.getTrader().getCity().equals("剑桥")).map(Transaction::getValue).forEach(System.out::println); + + Optional first7 = list.stream().map(Transaction::getValue).sorted(Integer::compareTo).limit(1).findFirst(); + + list.stream().min(comparing(Transaction::getValue)); + + + + } +} From 074b4e58f1cc01629bf138f0ee6dd0f81ef69e4c Mon Sep 17 00:00:00 2001 From: vector Date: Mon, 8 Oct 2018 08:22:10 +0800 Subject: [PATCH 04/14] 6 ing --- .../java/lambdasinaction/chap3/Sorting.java | 14 +- .../java/lambdasinaction/chap6/Demo62.java | 26 +++ .../java/lambdasinaction/chap6/Grouping.java | 192 +++++++++--------- 3 files changed, 133 insertions(+), 99 deletions(-) create mode 100644 src/main/java/lambdasinaction/chap6/Demo62.java diff --git a/src/main/java/lambdasinaction/chap3/Sorting.java b/src/main/java/lambdasinaction/chap3/Sorting.java index 41acbe25..4b1d4453 100644 --- a/src/main/java/lambdasinaction/chap3/Sorting.java +++ b/src/main/java/lambdasinaction/chap3/Sorting.java @@ -1,6 +1,8 @@ package lambdasinaction.chap3; import java.util.*; +import java.util.function.Consumer; + import static java.util.Comparator.comparing; public class Sorting { @@ -28,7 +30,9 @@ public int compare(Apple a1, Apple a2){ // reshuffling things a little inventory.set(1, new Apple(20, "red")); - + + inventory.sort((Apple o1, Apple o2)->o1.getWeight().compareTo(o2.getWeight())); + // 3 // [Apple{color='red', weight=20}, Apple{color='green', weight=30}, Apple{color='green', weight=155}] inventory.sort((a1, a2) -> a1.getWeight().compareTo(a2.getWeight())); @@ -40,8 +44,12 @@ public int compare(Apple a1, Apple a2){ // 4 // [Apple{color='red', weight=10}, Apple{color='red', weight=20}, Apple{color='green', weight=155}] inventory.sort(comparing(Apple::getWeight)); - System.out.println(inventory); - } + System.out.println(inventory); + + String si = "123"; + int i = Integer.parseInt(si); + + } public static class Apple { private Integer weight = 0; diff --git a/src/main/java/lambdasinaction/chap6/Demo62.java b/src/main/java/lambdasinaction/chap6/Demo62.java new file mode 100644 index 00000000..f829a260 --- /dev/null +++ b/src/main/java/lambdasinaction/chap6/Demo62.java @@ -0,0 +1,26 @@ +package lambdasinaction.chap6; + +import java.util.Arrays; +import java.util.List; + +public class Demo62 { + public static List transactions = Arrays + .asList( new GroupingTransactions.Transaction(GroupingTransactions.Currency.EUR, 1500.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.USD, 2300.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.GBP, 9900.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.EUR, 1100.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.JPY, 7800.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.CHF, 6700.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.EUR, 5600.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.USD, 4500.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.CHF, 3400.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.GBP, 3200.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.USD, 4600.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.JPY, 5700.0), + new GroupingTransactions.Transaction(GroupingTransactions.Currency.EUR, 6800.0) ); + + public static void main(String[] args) { + System.out.println(transactions.size()); + System.out.println(transactions.stream().count()); + } +} diff --git a/src/main/java/lambdasinaction/chap6/Grouping.java b/src/main/java/lambdasinaction/chap6/Grouping.java index 37aa39a4..9105cc80 100644 --- a/src/main/java/lambdasinaction/chap6/Grouping.java +++ b/src/main/java/lambdasinaction/chap6/Grouping.java @@ -1,96 +1,96 @@ -//package lambdasinaction.chap6; -// -//import java.util.*; -// -//import static java.util.stream.Collectors.*; -//import static lambdasinaction.chap6.Dish.dishTags; -//import static lambdasinaction.chap6.Dish.menu; -// -//public class Grouping { -// -// enum CaloricLevel { DIET, NORMAL, FAT }; -// -// public static void main(String ... args) { -// System.out.println("Dishes grouped by type: " + groupDishesByType()); -// System.out.println("Dish names grouped by type: " + groupDishNamesByType()); -// System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); -// System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); -// System.out.println("Dishes grouped by caloric level: " + groupDishesByCaloricLevel()); -// System.out.println("Dishes grouped by type and caloric level: " + groupDishedByTypeAndCaloricLevel()); -// System.out.println("Count dishes in groups: " + countDishesInGroups()); -// System.out.println("Most caloric dishes by type: " + mostCaloricDishesByType()); -// System.out.println("Most caloric dishes by type: " + mostCaloricDishesByTypeWithoutOprionals()); -// System.out.println("Sum calories by type: " + sumCaloriesByType()); -// System.out.println("Caloric levels by type: " + caloricLevelsByType()); -// } -// -// private static Map> groupDishesByType() { -// return menu.stream().collect(groupingBy(Dish::getType)); -// } -// -// private static Map> groupDishNamesByType() { -// return menu.stream().collect(groupingBy(Dish::getType, mapping(Dish::getName, toList()))); -// } -// -// private static Map> groupDishTagsByType() { -// return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); -// } -// -// private static Map> groupCaloricDishesByType() { -//// return menu.stream().filter(dish -> dish.getCalories() > 500).collect(groupingBy(Dish::getType)); -// return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); -// } -// -// private static Map> groupDishesByCaloricLevel() { -// return menu.stream().collect( -// groupingBy(dish -> { -// if (dish.getCalories() <= 400) return CaloricLevel.DIET; -// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; -// else return CaloricLevel.FAT; -// } )); -// } -// -// private static Map>> groupDishedByTypeAndCaloricLevel() { -// return menu.stream().collect( -// groupingBy(Dish::getType, -// groupingBy((Dish dish) -> { -// if (dish.getCalories() <= 400) return CaloricLevel.DIET; -// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; -// else return CaloricLevel.FAT; -// } ) -// ) -// ); -// } -// -// private static Map countDishesInGroups() { -// return menu.stream().collect(groupingBy(Dish::getType, counting())); -// } -// -// private static Map> mostCaloricDishesByType() { -// return menu.stream().collect( -// groupingBy(Dish::getType, -// reducing((Dish d1, Dish d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); -// } -// -// private static Map mostCaloricDishesByTypeWithoutOprionals() { -// return menu.stream().collect( -// groupingBy(Dish::getType, -// collectingAndThen( -// reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2), -// Optional::get))); -// } -// -// private static Map sumCaloriesByType() { -// return menu.stream().collect(groupingBy(Dish::getType, -// summingInt(Dish::getCalories))); -// } -// -// private static Map> caloricLevelsByType() { -// return menu.stream().collect( -// groupingBy(Dish::getType, mapping( -// dish -> { if (dish.getCalories() <= 400) return CaloricLevel.DIET; -// else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; -// else return CaloricLevel.FAT; }, -// toSet() ))); -// } -//} +package lambdasinaction.chap6; + +import java.util.*; + +import static java.util.stream.Collectors.*; +import static lambdasinaction.chap6.Dish.dishTags; +import static lambdasinaction.chap6.Dish.menu; + +public class Grouping { + + enum CaloricLevel { DIET, NORMAL, FAT }; + + public static void main(String ... args) { + System.out.println("Dishes grouped by type: " + groupDishesByType()); + System.out.println("Dish names grouped by type: " + groupDishNamesByType()); + System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); + System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); + System.out.println("Dishes grouped by caloric level: " + groupDishesByCaloricLevel()); + System.out.println("Dishes grouped by type and caloric level: " + groupDishedByTypeAndCaloricLevel()); + System.out.println("Count dishes in groups: " + countDishesInGroups()); + System.out.println("Most caloric dishes by type: " + mostCaloricDishesByType()); + System.out.println("Most caloric dishes by type: " + mostCaloricDishesByTypeWithoutOprionals()); + System.out.println("Sum calories by type: " + sumCaloriesByType()); + System.out.println("Caloric levels by type: " + caloricLevelsByType()); + } + + private static Map> groupDishesByType() { + return menu.stream().collect(groupingBy(Dish::getType)); + } + + private static Map> groupDishNamesByType() { + return menu.stream().collect(groupingBy(Dish::getType, mapping(Dish::getName, toList()))); + } + + private static Map> groupDishTagsByType() { + return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); + } + + private static Map> groupCaloricDishesByType() { +// return menu.stream().filter(dish -> dish.getCalories() > 500).collect(groupingBy(Dish::getType)); + return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); + } + + private static Map> groupDishesByCaloricLevel() { + return menu.stream().collect( + groupingBy(dish -> { + if (dish.getCalories() <= 400) return CaloricLevel.DIET; + else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; + else return CaloricLevel.FAT; + } )); + } + + private static Map>> groupDishedByTypeAndCaloricLevel() { + return menu.stream().collect( + groupingBy(Dish::getType, + groupingBy((Dish dish) -> { + if (dish.getCalories() <= 400) return CaloricLevel.DIET; + else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; + else return CaloricLevel.FAT; + } ) + ) + ); + } + + private static Map countDishesInGroups() { + return menu.stream().collect(groupingBy(Dish::getType, counting())); + } + + private static Map> mostCaloricDishesByType() { + return menu.stream().collect( + groupingBy(Dish::getType, + reducing((Dish d1, Dish d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); + } + + private static Map mostCaloricDishesByTypeWithoutOprionals() { + return menu.stream().collect( + groupingBy(Dish::getType, + collectingAndThen( + reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2), + Optional::get))); + } + + private static Map sumCaloriesByType() { + return menu.stream().collect(groupingBy(Dish::getType, + summingInt(Dish::getCalories))); + } + + private static Map> caloricLevelsByType() { + return menu.stream().collect( + groupingBy(Dish::getType, mapping( + dish -> { if (dish.getCalories() <= 400) return CaloricLevel.DIET; + else if (dish.getCalories() <= 700) return CaloricLevel.NORMAL; + else return CaloricLevel.FAT; }, + toSet() ))); + } +} From 8028e09d2ce4a58f8a151f7f5025b9b58153f69c Mon Sep 17 00:00:00 2001 From: vector Date: Mon, 8 Oct 2018 19:44:07 +0800 Subject: [PATCH 05/14] 'update' --- .../java/lambdasinaction/chap6/Grouping.java | 26 ++- .../chap6/PartitionPrimeNumbers.java | 207 +++++++++--------- .../lambdasinaction/chap6/Partitioning.java | 6 +- .../java/lambdasinaction/chap6/Reducing.java | 18 +- .../chap6/ToListCollector.java | 1 + 5 files changed, 144 insertions(+), 114 deletions(-) diff --git a/src/main/java/lambdasinaction/chap6/Grouping.java b/src/main/java/lambdasinaction/chap6/Grouping.java index 9105cc80..d2642a7f 100644 --- a/src/main/java/lambdasinaction/chap6/Grouping.java +++ b/src/main/java/lambdasinaction/chap6/Grouping.java @@ -13,8 +13,8 @@ enum CaloricLevel { DIET, NORMAL, FAT }; public static void main(String ... args) { System.out.println("Dishes grouped by type: " + groupDishesByType()); System.out.println("Dish names grouped by type: " + groupDishNamesByType()); - System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); - System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); +// System.out.println("Dish tags grouped by type: " + groupDishTagsByType()); +// System.out.println("Caloric dishes grouped by type: " + groupCaloricDishesByType()); System.out.println("Dishes grouped by caloric level: " + groupDishesByCaloricLevel()); System.out.println("Dishes grouped by type and caloric level: " + groupDishedByTypeAndCaloricLevel()); System.out.println("Count dishes in groups: " + countDishesInGroups()); @@ -32,14 +32,14 @@ private static Map> groupDishNamesByType() { return menu.stream().collect(groupingBy(Dish::getType, mapping(Dish::getName, toList()))); } - private static Map> groupDishTagsByType() { - return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); - } - - private static Map> groupCaloricDishesByType() { +// private static Map> groupDishTagsByType() { +// return menu.stream().collect(groupingBy(Dish::getType, flatMapping(dish -> dishTags.get( dish.getName() ).stream(), toSet()))); +// } +// +// private static Map> groupCaloricDishesByType() { // return menu.stream().filter(dish -> dish.getCalories() > 500).collect(groupingBy(Dish::getType)); - return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); - } +// return menu.stream().collect(groupingBy(Dish::getType, filtering(dish -> dish.getCalories() > 500, toList()))); +// } private static Map> groupDishesByCaloricLevel() { return menu.stream().collect( @@ -63,16 +63,22 @@ private static Map>> groupDishedByTypeAn } private static Map countDishesInGroups() { + Map collect = menu.stream().collect(groupingBy(Dish::getType, counting())); return menu.stream().collect(groupingBy(Dish::getType, counting())); } private static Map> mostCaloricDishesByType() { + menu.stream().collect(groupingBy(Dish::getType, reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); + + return menu.stream().collect( groupingBy(Dish::getType, reducing((Dish d1, Dish d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2))); } private static Map mostCaloricDishesByTypeWithoutOprionals() { + + return menu.stream().collect( groupingBy(Dish::getType, collectingAndThen( @@ -86,6 +92,8 @@ private static Map sumCaloriesByType() { } private static Map> caloricLevelsByType() { + + return menu.stream().collect( groupingBy(Dish::getType, mapping( dish -> { if (dish.getCalories() <= 400) return CaloricLevel.DIET; diff --git a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java index 04de7674..d1847143 100644 --- a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java +++ b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java @@ -1,106 +1,107 @@ -//package lambdasinaction.chap6; -// -//import java.util.*; -//import java.util.function.*; -//import java.util.stream.*; -// -//import static java.util.stream.Collectors.*; -//import static java.util.stream.Collector.Characteristics.*; -// -//public class PartitionPrimeNumbers { -// -// public static void main(String ... args) { -// System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimes(100)); +package lambdasinaction.chap6; + +import java.util.*; +import java.util.function.*; +import java.util.stream.*; + +import static java.util.stream.Collectors.*; +import static java.util.stream.Collector.Characteristics.*; + +public class PartitionPrimeNumbers { + + public static void main(String ... args) { + System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimes(100)); // System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimesWithCustomCollector(100)); -// -// } -// -// public static Map> partitionPrimes(int n) { -// return IntStream.rangeClosed(2, n).boxed() -// .collect(partitioningBy(candidate -> isPrime(candidate))); -// } -// -// public static boolean isPrime(int candidate) { -// return IntStream.rangeClosed(2, candidate-1) -// .limit((long) Math.floor(Math.sqrt((double) candidate)) - 1) -// .noneMatch(i -> candidate % i == 0); -// } -// -// public static Map> partitionPrimesWithCustomCollector(int n) { -// return IntStream.rangeClosed(2, n).boxed().collect(new PrimeNumbersCollector()); -// } -// -// public static boolean isPrime(List primes, Integer candidate) { + + } + + public static Map> partitionPrimes(int n) { + return IntStream.rangeClosed(2, n).boxed() + .collect(partitioningBy(candidate -> isPrime(candidate))); + } + + public static boolean isPrime(int candidate) { + return IntStream.rangeClosed(2, candidate-1) + .limit((long) Math.floor(Math.sqrt((double) candidate)) - 1) + .noneMatch(i -> candidate % i == 0); + } + + public static Map> partitionPrimesWithCustomCollector(int n) { + return IntStream.rangeClosed(2, n).boxed().collect(new PrimeNumbersCollector()); + } + + public static boolean isPrime(List primes, Integer candidate) { // double candidateRoot = Math.sqrt((double) candidate); -// //return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); + //return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); // return primes.stream().takeWhile(i -> i <= candidateRoot).noneMatch(i -> candidate % i == 0); -// } -///* -// public static List takeWhile(List list, Predicate p) { -// int i = 0; -// for (A item : list) { -// if (!p.test(item)) { -// return list.subList(0, i); -// } -// i++; -// } -// return list; -// } -//*/ -// public static class PrimeNumbersCollector -// implements Collector>, Map>> { -// -// @Override -// public Supplier>> supplier() { -// return () -> new HashMap>() {{ -// put(true, new ArrayList()); -// put(false, new ArrayList()); -// }}; -// } -// -// @Override -// public BiConsumer>, Integer> accumulator() { -// return (Map> acc, Integer candidate) -> { -// acc.get( isPrime( acc.get(true), -// candidate) ) -// .add(candidate); -// }; -// } -// -// @Override -// public BinaryOperator>> combiner() { -// return (Map> map1, Map> map2) -> { -// map1.get(true).addAll(map2.get(true)); -// map1.get(false).addAll(map2.get(false)); -// return map1; -// }; -// } -// -// @Override -// public Function>, Map>> finisher() { -// return i -> i; -// } -// -// @Override -// public Set characteristics() { -// return Collections.unmodifiableSet(EnumSet.of(IDENTITY_FINISH)); -// } -// } -// -// public Map> partitionPrimesWithInlineCollector(int n) { -// return Stream.iterate(2, i -> i + 1).limit(n) -// .collect( -// () -> new HashMap>() {{ -// put(true, new ArrayList()); -// put(false, new ArrayList()); -// }}, -// (acc, candidate) -> { -// acc.get( isPrime(acc.get(true), candidate) ) -// .add(candidate); -// }, -// (map1, map2) -> { -// map1.get(true).addAll(map2.get(true)); -// map1.get(false).addAll(map2.get(false)); -// }); -// } -//} + return false; + } +/* + public static List takeWhile(List list, Predicate p) { + int i = 0; + for (A item : list) { + if (!p.test(item)) { + return list.subList(0, i); + } + i++; + } + return list; + } +*/ + public static class PrimeNumbersCollector + implements Collector>, Map>> { + + @Override + public Supplier>> supplier() { + return () -> new HashMap>() {{ + put(true, new ArrayList()); + put(false, new ArrayList()); + }}; + } + + @Override + public BiConsumer>, Integer> accumulator() { + return (Map> acc, Integer candidate) -> { + acc.get( isPrime( acc.get(true), + candidate) ) + .add(candidate); + }; + } + + @Override + public BinaryOperator>> combiner() { + return (Map> map1, Map> map2) -> { + map1.get(true).addAll(map2.get(true)); + map1.get(false).addAll(map2.get(false)); + return map1; + }; + } + + @Override + public Function>, Map>> finisher() { + return i -> i; + } + + @Override + public Set characteristics() { + return Collections.unmodifiableSet(EnumSet.of(IDENTITY_FINISH)); + } + } + + public Map> partitionPrimesWithInlineCollector(int n) { + return Stream.iterate(2, i -> i + 1).limit(n) + .collect( + () -> new HashMap>() {{ + put(true, new ArrayList()); + put(false, new ArrayList()); + }}, + (acc, candidate) -> { + acc.get( isPrime(acc.get(true), candidate) ) + .add(candidate); + }, + (map1, map2) -> { + map1.get(true).addAll(map2.get(true)); + map1.get(false).addAll(map2.get(false)); + }); + } +} diff --git a/src/main/java/lambdasinaction/chap6/Partitioning.java b/src/main/java/lambdasinaction/chap6/Partitioning.java index 2ec8dc79..7dfad9b1 100644 --- a/src/main/java/lambdasinaction/chap6/Partitioning.java +++ b/src/main/java/lambdasinaction/chap6/Partitioning.java @@ -8,7 +8,7 @@ public class Partitioning { - public static void main(String ... args) { + public static void main(String... args) { System.out.println("Dishes partitioned by vegetarian: " + partitionByVegeterian()); System.out.println("Vegetarian Dishes by type: " + vegetarianDishesByType()); System.out.println("Most caloric dishes by vegetarian: " + mostCaloricPartitionedByVegetarian()); @@ -23,6 +23,10 @@ private static Map>> vegetarianDishesByType() } private static Object mostCaloricPartitionedByVegetarian() { + + Map collect = menu.stream().collect(partitioningBy(Dish::isVegetarian, collectingAndThen(maxBy(comparingInt(Dish::getCalories)), Optional::get))); + System.out.println(collect); + return menu.stream().collect( partitioningBy(Dish::isVegetarian, collectingAndThen( diff --git a/src/main/java/lambdasinaction/chap6/Reducing.java b/src/main/java/lambdasinaction/chap6/Reducing.java index fb7cf971..44973e3e 100644 --- a/src/main/java/lambdasinaction/chap6/Reducing.java +++ b/src/main/java/lambdasinaction/chap6/Reducing.java @@ -1,15 +1,18 @@ package lambdasinaction.chap6; +import java.util.function.BiFunction; + import static java.util.stream.Collectors.*; import static lambdasinaction.chap6.Dish.menu; public class Reducing { - public static void main(String ... args) { + public static void main(String... args) { System.out.println("Total calories in menu: " + calculateTotalCalories()); System.out.println("Total calories in menu: " + calculateTotalCaloriesWithMethodReference()); System.out.println("Total calories in menu: " + calculateTotalCaloriesWithoutCollectors()); System.out.println("Total calories in menu: " + calculateTotalCaloriesUsingSum()); + System.out.println("Total calories in menu: " + oldCount()); } private static int calculateTotalCalories() { @@ -27,4 +30,17 @@ private static int calculateTotalCaloriesWithoutCollectors() { private static int calculateTotalCaloriesUsingSum() { return menu.stream().mapToInt(Dish::getCalories).sum(); } + + private static int oldCount() { + menu.stream().map(Dish::getCalories).reduce(Integer::sum); + menu.stream().mapToInt(Dish::getCalories).sum(); + + menu.stream().collect(reducing(0, Dish::getCalories, Integer::sum)); + + int sum = 0; + for (Dish dish : menu) { + sum += dish.getCalories(); + } + return sum; + } } \ No newline at end of file diff --git a/src/main/java/lambdasinaction/chap6/ToListCollector.java b/src/main/java/lambdasinaction/chap6/ToListCollector.java index 0621d96a..05f613ca 100644 --- a/src/main/java/lambdasinaction/chap6/ToListCollector.java +++ b/src/main/java/lambdasinaction/chap6/ToListCollector.java @@ -9,6 +9,7 @@ public class ToListCollector implements Collector, List> { @Override public Supplier> supplier() { + return () -> new ArrayList(); } From 4e9591bafb529cd4ebd4fec837f7ff2ec9deeae5 Mon Sep 17 00:00:00 2001 From: vector Date: Tue, 9 Oct 2018 08:37:59 +0800 Subject: [PATCH 06/14] update --- .../chap6/CollectorHarness.java | 44 +++++++++---------- .../chap6/PartitionPrimeNumbers.java | 29 +++++++----- 2 files changed, 41 insertions(+), 32 deletions(-) diff --git a/src/main/java/lambdasinaction/chap6/CollectorHarness.java b/src/main/java/lambdasinaction/chap6/CollectorHarness.java index 46bab3b0..d8049d2a 100644 --- a/src/main/java/lambdasinaction/chap6/CollectorHarness.java +++ b/src/main/java/lambdasinaction/chap6/CollectorHarness.java @@ -1,23 +1,23 @@ -//package lambdasinaction.chap6; -// -//import java.util.function.*; -// -//public class CollectorHarness { -// -// public static void main(String[] args) { -// //System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimes) + " msecs"); +package lambdasinaction.chap6; + +import java.util.function.*; + +public class CollectorHarness { + + public static void main(String[] args) { + System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimes) + " msecs"); // System.out.println("Partitioning done in: " + execute(PartitionPrimeNumbers::partitionPrimesWithCustomCollector) + " msecs" ); -// } -// -// private static long execute(Consumer primePartitioner) { -// long fastest = Long.MAX_VALUE; -// for (int i = 0; i < 10; i++) { -// long start = System.nanoTime(); -// primePartitioner.accept(1_000_000); -// long duration = (System.nanoTime() - start) / 1_000_000; -// if (duration < fastest) fastest = duration; -// System.out.println("done in " + duration); -// } -// return fastest; -// } -//} + } + + private static long execute(Consumer primePartitioner) { + long fastest = Long.MAX_VALUE; + for (int i = 0; i < 10; i++) { + long start = System.nanoTime(); + primePartitioner.accept(1_000_000); + long duration = (System.nanoTime() - start) / 1_000_000; + if (duration < fastest) fastest = duration; + System.out.println("done in " + duration); + } + return fastest; + } +} diff --git a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java index d1847143..cd4c3990 100644 --- a/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java +++ b/src/main/java/lambdasinaction/chap6/PartitionPrimeNumbers.java @@ -11,7 +11,7 @@ public class PartitionPrimeNumbers { public static void main(String ... args) { System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimes(100)); -// System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimesWithCustomCollector(100)); + System.out.println("Numbers partitioned in prime and non-prime: " + partitionPrimesWithCustomCollector(100)); } @@ -31,12 +31,11 @@ public static Map> partitionPrimesWithCustomCollector(int } public static boolean isPrime(List primes, Integer candidate) { -// double candidateRoot = Math.sqrt((double) candidate); - //return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); + double candidateRoot = Math.sqrt((double) candidate); + return takeWhile(primes, i -> i <= candidateRoot).stream().noneMatch(i -> candidate % i == 0); // return primes.stream().takeWhile(i -> i <= candidateRoot).noneMatch(i -> candidate % i == 0); - return false; +// return false; } -/* public static List takeWhile(List list, Predicate p) { int i = 0; for (A item : list) { @@ -47,16 +46,26 @@ public static List takeWhile(List list, Predicate p) { } return list; } -*/ + public static class PrimeNumbersCollector implements Collector>, Map>> { @Override public Supplier>> supplier() { - return () -> new HashMap>() {{ - put(true, new ArrayList()); - put(false, new ArrayList()); - }}; + return () -> + new HashMap>() {{ + put(true,new ArrayList()); + } + }; + + +// booleanListHashMap.put(true,new ArrayList<>()); +// booleanListHashMap.put(false, new ArrayList<>()); +// return booleanListHashMap; +// } return () -> new HashMap>() {{ +// put(true, new ArrayList()); +// put(false, new ArrayList()); +// }}; } @Override From b21c2b13ef3cead3aa44944d164bb429dede7dbe Mon Sep 17 00:00:00 2001 From: vector Date: Thu, 11 Oct 2018 22:58:37 +0800 Subject: [PATCH 07/14] how to use lambda in slef --- .../lambdasinaction/chap10/OptionalMain.java | 90 ++++++++++++++----- 1 file changed, 66 insertions(+), 24 deletions(-) diff --git a/src/main/java/lambdasinaction/chap10/OptionalMain.java b/src/main/java/lambdasinaction/chap10/OptionalMain.java index 56d742eb..2d730e3b 100644 --- a/src/main/java/lambdasinaction/chap10/OptionalMain.java +++ b/src/main/java/lambdasinaction/chap10/OptionalMain.java @@ -1,24 +1,66 @@ -//package lambdasinaction.chap10; -// -//import java.util.*; -// -//import static java.util.stream.Collectors.toSet; -// -//public class OptionalMain { -// -// public String getCarInsuranceName(Optional person) { -// return person.flatMap(Person::getCar) -// .flatMap(Car::getInsurance) -// .map(Insurance::getName) -// .orElse("Unknown"); -// } -// -// public Set getCarInsuranceNames(List persons) { -// return persons.stream() -// .map(Person::getCar) -// .map(optCar -> optCar.flatMap(Car::getInsurance)) -// .map(optInsurance -> optInsurance.map(Insurance::getName)) -// .flatMap(Optional::stream) -// .collect(toSet()); -// } -//} +package lambdasinaction.chap10; + +import java.util.*; +import java.util.function.Predicate; +import java.util.function.Supplier; +import java.util.stream.Collectors; +import java.util.stream.IntStream; +import java.util.stream.Stream; + +import static java.util.stream.Collectors.toSet; + +public class OptionalMain { + + public static void main(String[] args) { + Stream stream = Stream.of("lamurudu", "Okanbi", "Oduduwa"); + Optional f = stream.filter(name -> name.startsWith("L")).findFirst(); + String lambda = f.orElse("Lambda"); + // String lambda = f.orElseGet(() -> "Lambda"); + f.ifPresent(s -> { + s = s.toUpperCase(); + System.out.println(s); + }); + System.out.println(lambda); + + + Optional.ofNullable("Jackson").filter(s->s.equals("Jackson")).ifPresent(s-> System.out.println(s+"~~~")); + + Stream.of("lamurudu", "Okanbi", "Oduduwa").filter(s -> s.contains("c")).findFirst().ifPresent(s-> System.out.println(123)); + + Set words = new HashSet<>(Arrays.asList("this", "is", "a", "stream", "of", "strings")); + Optional firstString = words.stream() + .findFirst(); + System.out.println(firstString); + + List equal=IntStream.range(0, 100) + .mapToObj(i->new String("test")) // don't do this in normal code + .collect(Collectors.toList()); + Map map = IntStream.range(0, equal.size()) + .collect(IdentityHashMap::new, (m,i)->m.put(equal.get(i),i), Map::putAll); + + equal.parallelStream().distinct().map(map::get) + .findFirst().ifPresent(System.out::println); + + + + Predicate startsWithJ = (n) -> n.startsWith("J"); + Predicate fourLetterLong = (n) -> n.length() == 4; + Predicate containsBig = (n) -> n.contains("A"); + Stream.of("lamurudu", "Jack", "Oduduwa","Jbulsu Abas") + .filter(startsWithJ.and(fourLetterLong.or(containsBig))) + .forEach((n) -> System.out.print("nName, which starts with 'J' and four letter long is : " + n)); + + } + + public String getCarInsuranceName(Optional person) { + return person.flatMap(Person::getCar).flatMap(Car::getInsurance).map(Insurance::getName).orElse("Unknown"); + } + // public Set getCarInsuranceNames(List persons) { + // return persons.stream() + // .map(Person::getCar) + // .map(optCar -> optCar.flatMap(Car::getInsurance)) + // .map(optInsurance -> optInsurance.map(Insurance::getName)) + // .flatMap(Optional::stream) + // .collect(toSet()); + // } +} From 930ddfcf1e01c01d664cfeabbdea5f9c143b8af0 Mon Sep 17 00:00:00 2001 From: vector Date: Fri, 12 Oct 2018 09:33:49 +0800 Subject: [PATCH 08/14] 'update' --- .../java/lambdasinaction/chap10/Demo103.java | 23 +++++++++++ .../java/lambdasinaction/chap10/Demo104.java | 36 ++++++++++++++++ .../chap10/OperationsWithOptional.java | 41 ++++++++++--------- .../lambdasinaction/chap10/OptionalMain.java | 32 +++++++-------- .../java/lambdasinaction/chap7/Demo71.java | 30 ++++++++++++++ src/main/java/lambdasinaction/chap8/Peek.java | 2 +- 6 files changed, 127 insertions(+), 37 deletions(-) create mode 100644 src/main/java/lambdasinaction/chap10/Demo103.java create mode 100644 src/main/java/lambdasinaction/chap10/Demo104.java create mode 100644 src/main/java/lambdasinaction/chap7/Demo71.java diff --git a/src/main/java/lambdasinaction/chap10/Demo103.java b/src/main/java/lambdasinaction/chap10/Demo103.java new file mode 100644 index 00000000..bae13b66 --- /dev/null +++ b/src/main/java/lambdasinaction/chap10/Demo103.java @@ -0,0 +1,23 @@ +package lambdasinaction.chap10; + +import java.util.Optional; +import java.util.function.Consumer; + +/** + * @author vector + * @date: 2018/10/10 0010 11:29 + */ +public class Demo103 { + public static void main(String[] args) { + Person person = new Person(); + Optional car = person.getCar(); + System.out.println(car.orElse(new Car())); + car.ifPresent(System.out::println); + ; + + +// Optional optCar2 = Optional.of(car) + + + } +} diff --git a/src/main/java/lambdasinaction/chap10/Demo104.java b/src/main/java/lambdasinaction/chap10/Demo104.java new file mode 100644 index 00000000..93fb3c8c --- /dev/null +++ b/src/main/java/lambdasinaction/chap10/Demo104.java @@ -0,0 +1,36 @@ +package lambdasinaction.chap10; + +import java.util.HashMap; +import java.util.Map; +import java.util.Optional; + +/** + * @author vector + * @date: 2018/10/10 0010 14:00 + */ +public class Demo104 { + public static void main(String[] args) { + Map map = new HashMap<>(); + + map.put("a", "sadfas"); + map.put("b", "sadfas1"); + map.put("c", "sadfas2"); + map.put("d", "sadfas3"); + + String e = map.get("e"); + System.out.println(e); + + Optional e1 = Optional.ofNullable(map.get("e")); + String s = Optional.ofNullable(map.get("e")).orElse("unknown key"); + System.out.println(s); + + } + + public static Optional stringToInt(String s) { + try { + return Optional.of(Integer.parseInt(s)); + } catch (NumberFormatException e) { + return Optional.empty(); + } + } +} diff --git a/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java b/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java index 42651b46..23fc2250 100644 --- a/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java +++ b/src/main/java/lambdasinaction/chap10/OperationsWithOptional.java @@ -1,25 +1,26 @@ -//package lambdasinaction.chap10; -// -//import java.util.*; -// -//import static java.util.Optional.of; -//import static java.util.Optional.empty; -// -//public class OperationsWithOptional { -// -// public static void main(String... args) { -// System.out.println(max(of(3), of(5))); -// System.out.println(max(empty(), of(5))); -// -// Optional opt1 = of(5); +package lambdasinaction.chap10; + +import java.util.*; + +import static java.util.Optional.of; +import static java.util.Optional.empty; + +public class OperationsWithOptional { + + public static void main(String... args) { + System.out.println(max(of(3), of(5))); + System.out.println(max(empty(), of(5))); + + Optional opt1 = of(5); + // Optional opt2 = opt1.or(() -> of(4)); // // System.out.println( // of(5).or(() -> of(4)) // ); -// } -// -// public static final Optional max(Optional i, Optional j) { -// return i.flatMap(a -> j.map(b -> Math.max(a, b))); -// } -//} + } + + public static final Optional max(Optional i, Optional j) { + return i.flatMap(a -> j.map(b -> Math.max(a, b))); + } +} diff --git a/src/main/java/lambdasinaction/chap10/OptionalMain.java b/src/main/java/lambdasinaction/chap10/OptionalMain.java index 56d742eb..7910e1b8 100644 --- a/src/main/java/lambdasinaction/chap10/OptionalMain.java +++ b/src/main/java/lambdasinaction/chap10/OptionalMain.java @@ -1,18 +1,18 @@ -//package lambdasinaction.chap10; -// -//import java.util.*; -// -//import static java.util.stream.Collectors.toSet; -// -//public class OptionalMain { -// -// public String getCarInsuranceName(Optional person) { -// return person.flatMap(Person::getCar) -// .flatMap(Car::getInsurance) -// .map(Insurance::getName) -// .orElse("Unknown"); -// } -// +package lambdasinaction.chap10; + +import java.util.*; + +import static java.util.stream.Collectors.toSet; + +public class OptionalMain { + + public String getCarInsuranceName(Optional person) { + return person.flatMap(Person::getCar) + .flatMap(Car::getInsurance) + .map(Insurance::getName) + .orElse("Unknown"); + } + // public Set getCarInsuranceNames(List persons) { // return persons.stream() // .map(Person::getCar) @@ -21,4 +21,4 @@ // .flatMap(Optional::stream) // .collect(toSet()); // } -//} +} diff --git a/src/main/java/lambdasinaction/chap7/Demo71.java b/src/main/java/lambdasinaction/chap7/Demo71.java new file mode 100644 index 00000000..ddba8693 --- /dev/null +++ b/src/main/java/lambdasinaction/chap7/Demo71.java @@ -0,0 +1,30 @@ +package lambdasinaction.chap7; + +import java.util.stream.Stream; + +/** + * @author vector + * @date: 2018/10/9 0009 11:21 + */ +public class Demo71 { + + public static long sequentialSum(int n) { + return Stream.iterate(1L, i -> i + 1).limit(n).reduce(0L, (l1, l2) -> l1 + l2); + } + + public static long parallelSum(int n) { + return Stream.iterate(1L, i -> i + 1).limit(n).parallel().reduce(0L, (l1, l2) -> l1 + l2); + } + + public static long iterativeSum(int n) { + long result = 0; + for (int i = 0; i < n; i++) { + result += i; + } + return result; + } + + public static void main(String[] args) { + + } +} diff --git a/src/main/java/lambdasinaction/chap8/Peek.java b/src/main/java/lambdasinaction/chap8/Peek.java index e25d68a4..01b839ce 100644 --- a/src/main/java/lambdasinaction/chap8/Peek.java +++ b/src/main/java/lambdasinaction/chap8/Peek.java @@ -10,7 +10,7 @@ public class Peek { public static void main(String[] args) { - List result = Stream.of(2, 3, 4, 5) + List result = Stream.of(2, 3, 4, 5, 13, 23) .peek(x -> System.out.println("taking from stream: " + x)).map(x -> x + 17) .peek(x -> System.out.println("after map: " + x)).filter(x -> x % 2 == 0) .peek(x -> System.out.println("after filter: " + x)).limit(3) From c74ff5e1abe11f80d91502c07f0a3d78b26a96cc Mon Sep 17 00:00:00 2001 From: vector Date: Tue, 16 Oct 2018 09:35:46 +0800 Subject: [PATCH 09/14] 'local' --- pom.xml | 7 ++ .../lambdasinaction/chap10/OptionalMain.java | 1 - src/test/java/TransformTest/Demo1.java | 70 +++++++++++++++++++ src/test/java/TransformTest/Demo2.java | 46 ++++++++++++ 4 files changed, 123 insertions(+), 1 deletion(-) create mode 100644 src/test/java/TransformTest/Demo1.java create mode 100644 src/test/java/TransformTest/Demo2.java diff --git a/pom.xml b/pom.xml index 37cbf712..b59ba066 100644 --- a/pom.xml +++ b/pom.xml @@ -28,6 +28,13 @@ junit 4.11 + + + org.apache.commons + commons-lang3 + 3.4 + + diff --git a/src/main/java/lambdasinaction/chap10/OptionalMain.java b/src/main/java/lambdasinaction/chap10/OptionalMain.java index 9cad2e26..0a4a1cbd 100644 --- a/src/main/java/lambdasinaction/chap10/OptionalMain.java +++ b/src/main/java/lambdasinaction/chap10/OptionalMain.java @@ -54,7 +54,6 @@ public static void main(String[] args) { Stream.of("lamurudu", "Jack", "Oduduwa", "Jbulsu Abas") .filter(startsWithJ.and(fourLetterLong.or(containsBig))) .forEach((n) -> System.out.print("nName, which starts with 'J' and four letter long is : " + n)); - } public String getCarInsuranceName(Optional person) { diff --git a/src/test/java/TransformTest/Demo1.java b/src/test/java/TransformTest/Demo1.java new file mode 100644 index 00000000..36c02ee0 --- /dev/null +++ b/src/test/java/TransformTest/Demo1.java @@ -0,0 +1,70 @@ +package TransformTest; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; + +/** + * @author vector + * @date: 2018/10/15 0015 11:47 + */ +public class Demo1 { + public static List getLongestList(List> lists) { + if (lists.isEmpty()) { + return new ArrayList<>(); + } + int index = 0; + int max = 0; + for (int i = 0; i < lists.size(); i++) { + List list = lists.get(i); + if (list.size() > max) { + index = i; + max = list.size(); + } + } + return lists.get(index); + } + + + public static List getLongestList2(List> lists) { + return lists.stream().max(Comparator.comparing(List::size)).orElse(Collections.emptyList()); +// List max = Collections.max(lists, Comparator.comparingInt(List::size)); +// return max; + + } + + public static void main(String[] args) { + List> bigList = new ArrayList>(){{ + add(new ArrayList(){{ + add("A"); + add("B"); + add("C"); + add("D"); + }}); + add(new ArrayList(){{ + add("a"); + add("b"); + add("c"); + }}); + add(new ArrayList(){{ + add("A"); + add("B"); + add("C"); + add("d"); + }}); + add(new ArrayList(){{ + add("A"); + add("B"); + }}); + }}; + System.out.println(bigList.size()); + for (int i = 0; i < 100; i++) { + System.out.println(getLongestList(bigList)); + System.out.println(getLongestList2(bigList)); + System.out.println(new ArrayList<>()); + System.out.println("===="); + } + + } +} diff --git a/src/test/java/TransformTest/Demo2.java b/src/test/java/TransformTest/Demo2.java new file mode 100644 index 00000000..7945283d --- /dev/null +++ b/src/test/java/TransformTest/Demo2.java @@ -0,0 +1,46 @@ +package TransformTest; + +import org.apache.commons.lang3.time.DateFormatUtils; +import org.apache.commons.lang3.time.DateUtils; + +import java.text.ParseException; +import java.util.Date; +import java.util.Objects; + +/** + * @author vector + * @date: 2018/10/15 0015 13:55 + */ +public class Demo2 { + public static boolean validDateTime(Date date, Date start, Date end) { + if (Objects.isNull(date) || Objects.isNull(start) ||Objects.isNull(end) ) { + return false; + } + if (date.after(start) && date.before(end) ) { + return true; + } + return false; + } + public static boolean validDateTime2(Date date, Date start, Date end) { + if (Objects.isNull(date)) { + return false; + } + if (Objects.isNull(start) || date.before(start)) { + return false; + } + if (Objects.isNull(end) || date.after(end)) { + return false; + } + return true; + } + + public static void main(String[] args) throws ParseException { + Date currentDate = new Date(); + Date start = DateFormatUtils.ISO_DATE_FORMAT.parse("2018-10-15"); + Date end = DateFormatUtils.ISO_DATE_FORMAT.parse("2070-01-01"); + + System.out.println(validDateTime(currentDate,start,end)); + System.out.println(validDateTime2(currentDate,start,end)); + } + +} From 3026b1a30ec5b68776e1c672f01898a8b5a938ec Mon Sep 17 00:00:00 2001 From: vector Date: Tue, 16 Oct 2018 09:35:58 +0800 Subject: [PATCH 10/14] local --- .../chap11/BestPriceFinder.java | 29 +++++- .../chap11/BestPriceFinderMain.java | 6 +- .../java/lambdasinaction/chap11/Discount.java | 5 ++ .../java/lambdasinaction/chap11/Quote.java | 49 ++++++----- .../chap11/standard/Resume.java | 44 ++++++++++ .../chap11/standard/StandardService.java | 88 +++++++++++++++++++ .../chap11/v1/BestPriceFinderMain.java | 10 +-- .../java/lambdasinaction/chap11/v1/Shop.java | 7 ++ .../chap12/DateTimeExamples.java | 10 ++- src/main/java/lambdasinaction/chap9/Body.java | 18 ++++ .../java/lambdasinaction/chap9/Sized.java | 9 ++ 11 files changed, 237 insertions(+), 38 deletions(-) create mode 100644 src/main/java/lambdasinaction/chap11/standard/Resume.java create mode 100644 src/main/java/lambdasinaction/chap11/standard/StandardService.java create mode 100644 src/main/java/lambdasinaction/chap9/Body.java create mode 100644 src/main/java/lambdasinaction/chap9/Sized.java diff --git a/src/main/java/lambdasinaction/chap11/BestPriceFinder.java b/src/main/java/lambdasinaction/chap11/BestPriceFinder.java index 51412e93..b8713d01 100644 --- a/src/main/java/lambdasinaction/chap11/BestPriceFinder.java +++ b/src/main/java/lambdasinaction/chap11/BestPriceFinder.java @@ -1,5 +1,7 @@ package lambdasinaction.chap11; +import com.sun.xml.internal.ws.util.CompletedFuture; + import java.util.Arrays; import java.util.List; import java.util.concurrent.CompletableFuture; @@ -27,6 +29,12 @@ public Thread newThread(Runnable r) { }); public List findPricesSequential(String product) { +// shops.stream().map(shop -> shop.getPrice(product)) +// .map(Quote::parse) +// .map(Discount::applyDiscount) +// .collect(Collectors.toList()); + + return shops.stream() .map(shop -> shop.getPrice(product)) .map(Quote::parse) @@ -42,10 +50,14 @@ public List findPricesParallel(String product) { .collect(Collectors.toList()); } - public List findPricesFuture(String product) { + /** + * 两个延时任务A,B，B的参数是A的结果，简单的说A与B有依赖的关系 + * @param product + * @return + */ + public List findPricesFuture(String product) { List> priceFutures = findPricesStream(product) - .collect(Collectors.>toList()); - + .collect(Collectors.toList()); return priceFutures.stream() .map(CompletableFuture::join) .collect(Collectors.toList()); @@ -67,4 +79,15 @@ public void printPricesStream(String product) { System.out.println("All shops have now responded in " + ((System.nanoTime() - start) / 1_000_000) + " msecs"); } + public void fun1143(String product) { + List> priceFutures = shops.stream() + .map(shop -> CompletableFuture.supplyAsync(() -> shop.getPrice(product), executor)) + .map(future -> future.thenApply(Quote::parse)).map(future -> future.thenCompose( + quote -> CompletableFuture.supplyAsync(() -> Discount.applyDiscount(quote), executor))) + .collect(Collectors.toList()); + priceFutures.stream().map(CompletableFuture::join).collect(Collectors.toList()); + + + } + } diff --git a/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java b/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java index 43ec8fba..ab4ba626 100644 --- a/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java +++ b/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java @@ -8,9 +8,9 @@ public class BestPriceFinderMain { private static BestPriceFinder bestPriceFinder = new BestPriceFinder(); public static void main(String[] args) { - execute("sequential", () -> bestPriceFinder.findPricesSequential("myPhone27S")); - execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); - execute("composed CompletableFuture", () -> bestPriceFinder.findPricesFuture("myPhone27S")); +// execute("sequential", () -> bestPriceFinder.findPricesSequential("myPhone27S")); +// execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); +// execute("composed CompletableFuture", () -> bestPriceFinder.findPricesFuture("myPhone27S")); bestPriceFinder.printPricesStream("myPhone27S"); } diff --git a/src/main/java/lambdasinaction/chap11/Discount.java b/src/main/java/lambdasinaction/chap11/Discount.java index 5624abd1..f01966ec 100644 --- a/src/main/java/lambdasinaction/chap11/Discount.java +++ b/src/main/java/lambdasinaction/chap11/Discount.java @@ -22,4 +22,9 @@ private static double apply(double price, Code code) { delay(); return format(price * (100 - code.percentage) / 100); } + + + public static void main(String[] args) { + + } } diff --git a/src/main/java/lambdasinaction/chap11/Quote.java b/src/main/java/lambdasinaction/chap11/Quote.java index 72dd81bf..0e7b9f7e 100644 --- a/src/main/java/lambdasinaction/chap11/Quote.java +++ b/src/main/java/lambdasinaction/chap11/Quote.java @@ -2,33 +2,34 @@ public class Quote { - private final String shopName; - private final double price; - private final Discount.Code discountCode; + private final String shopName; + private final double price; + private final Discount.Code discountCode; - public Quote(String shopName, double price, Discount.Code discountCode) { - this.shopName = shopName; - this.price = price; - this.discountCode = discountCode; - } + public Quote(String shopName, double price, Discount.Code discountCode) { + this.shopName = shopName; + this.price = price; + this.discountCode = discountCode; + } - public static Quote parse(String s) { - String[] split = s.split(":"); - String shopName = split[0]; - double price = Double.parseDouble(split[1]); - Discount.Code discountCode = Discount.Code.valueOf(split[2]); - return new Quote(shopName, price, discountCode); - } + public static Quote parse(String s) { + System.out.println("parse " + s); + String[] split = s.split(":"); + String shopName = split[0]; + double price = Double.parseDouble(split[1]); + Discount.Code discountCode = Discount.Code.valueOf(split[2]); + return new Quote(shopName, price, discountCode); + } - public String getShopName() { - return shopName; - } + public String getShopName() { + return shopName; + } - public double getPrice() { - return price; - } + public double getPrice() { + return price; + } - public Discount.Code getDiscountCode() { - return discountCode; - } + public Discount.Code getDiscountCode() { + return discountCode; + } } diff --git a/src/main/java/lambdasinaction/chap11/standard/Resume.java b/src/main/java/lambdasinaction/chap11/standard/Resume.java new file mode 100644 index 00000000..d633440e --- /dev/null +++ b/src/main/java/lambdasinaction/chap11/standard/Resume.java @@ -0,0 +1,44 @@ +package lambdasinaction.chap11.standard; + +public class Resume { + private String company; + + private String school; + + private String skill; + + private String title; + + public String getCompany() { + return company; + } + + public void setCompany(String company) { + this.company = company; + } + + public String getSchool() { + return school; + } + + public void setSchool(String school) { + this.school = school; + } + + public String getSkill() { + return skill; + } + + public void setSkill(String skill) { + this.skill = skill; + } + + public String getTitle() { + return title; + } + + public void setTitle(String title) { + this.title = title; + } + +} diff --git a/src/main/java/lambdasinaction/chap11/standard/StandardService.java b/src/main/java/lambdasinaction/chap11/standard/StandardService.java new file mode 100644 index 00000000..579d7378 --- /dev/null +++ b/src/main/java/lambdasinaction/chap11/standard/StandardService.java @@ -0,0 +1,88 @@ +package lambdasinaction.chap11.standard; + +import java.util.ArrayList; +import java.util.List; +import java.util.Random; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.Executor; +import java.util.concurrent.Executors; +import java.util.concurrent.ThreadFactory; + +public class StandardService { + + private final Executor executor = Executors.newFixedThreadPool(5, new ThreadFactory() { + @Override + public Thread newThread(Runnable r) { + Thread t = new Thread(r); + t.setDaemon(true); + return t; + } + }); + + + public String stadardCompany(String company) { + delay(100); + return "standard " + company; + } + + public String standardSchool(String schoole) { + delay(50); + return "standard " + schoole; + } + + public String standardSkill(String skill) { + delay(200); + return "standard " + skill; + } + + public String standardTitle(String title) { + delay(1000); + return "standard " + title; + } + + private void delay(int target) { + int delayMils = new Random().nextInt(target); + try { + Thread.sleep(delayMils); + } catch (InterruptedException e) { + e.printStackTrace(); + } + } + + public String buildTag(String com, String school, String skill, String title) { + return com + school + skill + title + "tag"; + } + + public void oldFun(List resumes) { + for (Resume resume : resumes) { + long start = System.nanoTime(); + String company = this.stadardCompany(resume.getCompany()); + String school= this.standardSchool(resume.getSchool()); + String skill = this.standardSkill(resume.getSkill()); + String title = this.standardTitle(resume.getTitle()); + System.out.println(this.buildTag(company, school, skill, title)); + long retrivalTime = ((System.nanoTime() - start) / 1_000_000); + System.out.println(retrivalTime); + } + } + + public void newFun(List resumes) { +// resumes.stream() +// .map(resume -> CompletableFuture.supplyAsync(() -> stadardCompany(resume.getCompany()), executor)) +// .map(task -> task +// .thenCompose(resume -> CompletableFuture.supplyAsync(()->standardSchool(resume.), executor))) +// .map(task -> task +// .thenCompose(resume -> CompletableFuture.supplyAsync(()->standardSchool(resume.gets), executor))); + + } + + public static void main(String[] args) { + Resume resume = new Resume(); + resume.setCompany("A"); + resume.setSchool("B"); + resume.setSkill("C"); + resume.setTitle("D"); + StandardService standardService = new StandardService(); +// standardService.oldFun(new ArrayList(){{add(resume)}}); + } +} diff --git a/src/main/java/lambdasinaction/chap11/v1/BestPriceFinderMain.java b/src/main/java/lambdasinaction/chap11/v1/BestPriceFinderMain.java index 5a74161a..fc32664b 100644 --- a/src/main/java/lambdasinaction/chap11/v1/BestPriceFinderMain.java +++ b/src/main/java/lambdasinaction/chap11/v1/BestPriceFinderMain.java @@ -8,12 +8,12 @@ public class BestPriceFinderMain { private static BestPriceFinder bestPriceFinder = new BestPriceFinder(); public static void main(String[] args) { - execute("sequential", () -> bestPriceFinder.findPricesSequential("myPhone27S")); - execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); +// execute("sequential", () -> bestPriceFinder.findPricesSequential("myPhone27S")); +// execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); execute("composed CompletableFuture", () -> bestPriceFinder.findPricesFuture("myPhone27S")); - execute("combined USD CompletableFuture", () -> bestPriceFinder.findPricesInUSD("myPhone27S")); - execute("combined USD CompletableFuture v2", () -> bestPriceFinder.findPricesInUSD2("myPhone27S")); - execute("combined USD CompletableFuture v3", () -> bestPriceFinder.findPricesInUSD3("myPhone27S")); +// execute("combined USD CompletableFuture", () -> bestPriceFinder.findPricesInUSD("myPhone27S")); +// execute("combined USD CompletableFuture v2", () -> bestPriceFinder.findPricesInUSD2("myPhone27S")); +// execute("combined USD CompletableFuture v3", () -> bestPriceFinder.findPricesInUSD3("myPhone27S")); } private static void execute(String msg, Supplier> s) { diff --git a/src/main/java/lambdasinaction/chap11/v1/Shop.java b/src/main/java/lambdasinaction/chap11/v1/Shop.java index cd3da975..e54fb064 100644 --- a/src/main/java/lambdasinaction/chap11/v1/Shop.java +++ b/src/main/java/lambdasinaction/chap11/v1/Shop.java @@ -38,4 +38,11 @@ public String getName() { return name; } + + public static void main(String[] args) { +// System.out.println(new Shop("yonwang").getPrice("apple")); + System.out.println(new Shop("yongwang").getPriceAsync("origin")); + + } + } diff --git a/src/main/java/lambdasinaction/chap12/DateTimeExamples.java b/src/main/java/lambdasinaction/chap12/DateTimeExamples.java index 46895cc5..7c9d6df7 100644 --- a/src/main/java/lambdasinaction/chap12/DateTimeExamples.java +++ b/src/main/java/lambdasinaction/chap12/DateTimeExamples.java @@ -32,10 +32,10 @@ protected DateFormat initialValue() { }; public static void main(String[] args) { - useOldDate(); +// useOldDate(); useLocalDate(); - useTemporalAdjuster(); - useDateFormatter(); +// useTemporalAdjuster(); +// useDateFormatter(); } private static void useOldDate() { @@ -154,4 +154,8 @@ private static void useDateFormatter() { System.out.println(date.format(complexFormatter)); } + private static void fun1211() { + LocalDate localDate = LocalDate.of(2014, 10, 15); + } + } diff --git a/src/main/java/lambdasinaction/chap9/Body.java b/src/main/java/lambdasinaction/chap9/Body.java new file mode 100644 index 00000000..ee3a0476 --- /dev/null +++ b/src/main/java/lambdasinaction/chap9/Body.java @@ -0,0 +1,18 @@ +package lambdasinaction.chap9; + +public class Body implements Sized { + + public static void main(String[] args) { + System.out.println(new Body().size()); + } + + @Override + public int size() { + return 20; + } + + @Override + public boolean isEmpty() { + return false; + } +} diff --git a/src/main/java/lambdasinaction/chap9/Sized.java b/src/main/java/lambdasinaction/chap9/Sized.java new file mode 100644 index 00000000..206dea5a --- /dev/null +++ b/src/main/java/lambdasinaction/chap9/Sized.java @@ -0,0 +1,9 @@ +package lambdasinaction.chap9; + +public interface Sized { + int size(); + + default boolean isEmpty() { + return size() == 0; + } +} From 76903fe80a16a260424be67c737a13c60e89eed9 Mon Sep 17 00:00:00 2001 From: vector Date: Tue, 16 Oct 2018 10:22:58 +0800 Subject: [PATCH 11/14] 'update' --- .../chap12/DateTimeExamples.java | 66 ++++++++++++++++--- 1 file changed, 58 insertions(+), 8 deletions(-) diff --git a/src/main/java/lambdasinaction/chap12/DateTimeExamples.java b/src/main/java/lambdasinaction/chap12/DateTimeExamples.java index 7c9d6df7..41193a55 100644 --- a/src/main/java/lambdasinaction/chap12/DateTimeExamples.java +++ b/src/main/java/lambdasinaction/chap12/DateTimeExamples.java @@ -5,13 +5,9 @@ import java.text.DateFormat; import java.text.SimpleDateFormat; -import java.time.DayOfWeek; -import java.time.Duration; -import java.time.Instant; -import java.time.LocalDate; -import java.time.LocalDateTime; -import java.time.LocalTime; -import java.time.Month; +import java.time.*; +import java.time.chrono.ChronoLocalDate; +import java.time.chrono.Chronology; import java.time.chrono.JapaneseDate; import java.time.format.DateTimeFormatter; import java.time.format.DateTimeFormatterBuilder; @@ -22,6 +18,7 @@ import java.util.Calendar; import java.util.Date; import java.util.Locale; +import java.util.TimeZone; public class DateTimeExamples { @@ -33,9 +30,13 @@ protected DateFormat initialValue() { public static void main(String[] args) { // useOldDate(); - useLocalDate(); +// useLocalDate(); // useTemporalAdjuster(); // useDateFormatter(); + + +// fun121(); + fun1222(); } private static void useOldDate() { @@ -158,4 +159,53 @@ private static void fun1211() { LocalDate localDate = LocalDate.of(2014, 10, 15); } + private static void fun121() { + LocalDate date = LocalDate.of(2014, 3, 18); + date = date.with(ChronoField.MONTH_OF_YEAR, 9); + date = date.plusYears(2).minusDays(10); + date.withYear(2011); + System.out.println(date); + } + + private static void fun122() { + LocalDate date = LocalDate.of(2018, 10, 16); + date.with(temporal -> { + DayOfWeek dow = DayOfWeek.of(temporal.get(ChronoField.DAY_OF_WEEK)); + int dayToAdd = 1; + if (dow == DayOfWeek.FRIDAY) { + dayToAdd = 3; + } else if (dow == DayOfWeek.SATURDAY) { + dayToAdd = 2; + } + return temporal.plus(dayToAdd, ChronoUnit.DAYS); + }); + } + + private static void fun1222() { + LocalDate date = LocalDate.of(2014, 10, 16); + String format = date.format(DateTimeFormatter.BASIC_ISO_DATE); + String format1 = date.format(DateTimeFormatter.ISO_LOCAL_DATE); + System.out.println(format+"|"+format1); + + LocalDate date1 = LocalDate.parse("20141016", DateTimeFormatter.BASIC_ISO_DATE); + LocalDate date2 = LocalDate.parse("2014-10-16", DateTimeFormatter.ISO_LOCAL_DATE); + + } + + private static void fun123() { + ZoneId romeZone = ZoneId.of("Europe/Rome"); + ZoneId zoneId = TimeZone.getDefault().toZoneId(); + + LocalDate date = LocalDate.of(2014, Month.MARCH, 18); + ZonedDateTime zonedDateTime = date.atStartOfDay(zoneId); + } + + private static void fun1231() { + ZoneOffset newYrokOffset = ZoneOffset.of("-05:00"); + Chronology japaneseChronology = Chronology.ofLocale(Locale.JAPAN); + ChronoLocalDate now = japaneseChronology.dateNow(); + + } + + } From 5599fb6db7ce2a5a1f4a8772f88a5988020516dc Mon Sep 17 00:00:00 2001 From: vector Date: Thu, 18 Oct 2018 15:02:27 +0800 Subject: [PATCH 12/14] =?UTF-8?q?=E6=B3=A8=E6=84=8Fparallelstream?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- pom.xml | 123 +++++++++--------- .../chap4/StreamParallellTest.java | 62 +++++++++ 2 files changed, 127 insertions(+), 58 deletions(-) create mode 100644 src/main/java/lambdasinaction/chap4/StreamParallellTest.java diff --git a/pom.xml b/pom.xml index b59ba066..02b3cc9f 100644 --- a/pom.xml +++ b/pom.xml @@ -7,67 +7,74 @@ manning lambdasinaction 1.0 - + - UTF-8 + UTF-8 - - - org.openjdk.jmh - jmh-core - 1.17.4 - - - org.openjdk.jmh - jmh-generator-annprocess - 1.17.4 - - - junit - junit - 4.11 - - - - org.apache.commons - commons-lang3 - 3.4 - + + + org.openjdk.jmh + jmh-core + 1.17.4 + + + org.openjdk.jmh + jmh-generator-annprocess + 1.17.4 + + + junit + junit + 4.11 + + + + org.apache.commons + commons-lang3 + 3.4 + + + + org.apache.commons + commons-collections4 + 4.1 + - + - - - - org.apache.maven.plugins - maven-compiler-plugin - 3.1 - - 1.8 - 1.8 - - - - org.apache.maven.plugins - maven-shade-plugin - - - package - - shade - - - benchmarks - - - org.openjdk.jmh.Main - - - - - - - - + + + + org.apache.maven.plugins + maven-compiler-plugin + 3.1 + + 1.8 + 1.8 + + + + org.apache.maven.plugins + maven-shade-plugin + + + package + + shade + + + benchmarks + + + org.openjdk.jmh.Main + + + + + + + + \ No newline at end of file diff --git a/src/main/java/lambdasinaction/chap4/StreamParallellTest.java b/src/main/java/lambdasinaction/chap4/StreamParallellTest.java new file mode 100644 index 00000000..b65c9a53 --- /dev/null +++ b/src/main/java/lambdasinaction/chap4/StreamParallellTest.java @@ -0,0 +1,62 @@ +package lambdasinaction.chap4; + +import org.apache.commons.collections4.ListUtils; + +import java.util.List; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +/** + * @author vector + * @date: 2018/10/18 0018 10:00 + * + * List> -> List + * + * 使用parallelstream需注意【共享对象的可变状态】 + * 如使用foreach就能改变其状态 + * 需要特别注意下 + */ +public class StreamParallellTest { + + public static List sum(List items,int count) { + List> listList = ListUtils.partition(items, count); + return listList.stream().flatMap(List::stream).map(StreamParallellTest::delayFun).collect(Collectors.toList()); + } + + public static List parallelSum(List items,int count) { + List> listList = ListUtils.partition(items, count); + return listList.parallelStream().flatMap(List::stream).map(StreamParallellTest::delayFun).collect(Collectors.toList()); + } + + public static String delayFun(int digist) { + try { + Thread.sleep(digist); + } catch (InterruptedException e) { + e.printStackTrace(); + } + return digist + ""; + } + + public static void main(String[] args) { + List items = IntStream.rangeClosed(1, 50).boxed().collect(Collectors.toList()); + System.out.println(items); + long s = System.currentTimeMillis(); + sum(items,10); + long e = System.currentTimeMillis(); + System.out.println((double)(e-s)/1_000 + "s"); + + long s1 = System.currentTimeMillis(); + parallelSum(items,10); + long e1 = System.currentTimeMillis(); + System.out.println((double)(e1-s1)/1_000 + "s"); +// for (int i = 0; i < 10; i++) { +// for (int j = 0; j < 10; j++) { +// long s1 = System.currentTimeMillis(); +// parallelSum(items,10); +// long e1 = System.currentTimeMillis(); +// System.out.println((double)(e1-s1)/1_000 + "s"); +// } +// System.out.println("============================"); +// } + } +} From cfce5b70e07457a114d2e3d12a9aa21d9fbdd3fa Mon Sep 17 00:00:00 2001 From: vector Date: Thu, 18 Oct 2018 15:18:38 +0800 Subject: [PATCH 13/14] =?UTF-8?q?=E6=94=B9=E5=8F=98=E6=B5=8B=E8=AF=95?= =?UTF-8?q?=E6=96=B9=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../chap11/BestPriceFinderMain.java | 4 +- .../chap4/StreamParallellTest.java | 39 ++++++++----------- 2 files changed, 19 insertions(+), 24 deletions(-) diff --git a/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java b/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java index ab4ba626..2b3da052 100644 --- a/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java +++ b/src/main/java/lambdasinaction/chap11/BestPriceFinderMain.java @@ -9,8 +9,8 @@ public class BestPriceFinderMain { public static void main(String[] args) { // execute("sequential", () -> bestPriceFinder.findPricesSequential("myPhone27S")); -// execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); -// execute("composed CompletableFuture", () -> bestPriceFinder.findPricesFuture("myPhone27S")); + execute("parallel", () -> bestPriceFinder.findPricesParallel("myPhone27S")); + execute("composed CompletableFuture", () -> bestPriceFinder.findPricesFuture("myPhone27S")); bestPriceFinder.printPricesStream("myPhone27S"); } diff --git a/src/main/java/lambdasinaction/chap4/StreamParallellTest.java b/src/main/java/lambdasinaction/chap4/StreamParallellTest.java index b65c9a53..30cfd663 100644 --- a/src/main/java/lambdasinaction/chap4/StreamParallellTest.java +++ b/src/main/java/lambdasinaction/chap4/StreamParallellTest.java @@ -3,27 +3,28 @@ import org.apache.commons.collections4.ListUtils; import java.util.List; +import java.util.function.Supplier; import java.util.stream.Collectors; import java.util.stream.IntStream; /** * @author vector * @date: 2018/10/18 0018 10:00 - * + *

* List> -> List - * + *

* 使用parallelstream需注意【共享对象的可变状态】 * 如使用foreach就能改变其状态 * 需要特别注意下 */ public class StreamParallellTest { - public static List sum(List items,int count) { + public static List sum(List items, int count) { List> listList = ListUtils.partition(items, count); return listList.stream().flatMap(List::stream).map(StreamParallellTest::delayFun).collect(Collectors.toList()); } - public static List parallelSum(List items,int count) { + public static List parallelSum(List items, int count) { List> listList = ListUtils.partition(items, count); return listList.parallelStream().flatMap(List::stream).map(StreamParallellTest::delayFun).collect(Collectors.toList()); } @@ -37,26 +38,20 @@ public static String delayFun(int digist) { return digist + ""; } + private static void execute(String msg, Supplier> supplier) { + long s = System.nanoTime(); + supplier.get(); + long e = System.nanoTime(); + long duration = (e - s) / 1_000_000; + + System.out.println(msg + " done in " + duration + " msecs"); + } + + public static void main(String[] args) { List items = IntStream.rangeClosed(1, 50).boxed().collect(Collectors.toList()); System.out.println(items); - long s = System.currentTimeMillis(); - sum(items,10); - long e = System.currentTimeMillis(); - System.out.println((double)(e-s)/1_000 + "s"); - - long s1 = System.currentTimeMillis(); - parallelSum(items,10); - long e1 = System.currentTimeMillis(); - System.out.println((double)(e1-s1)/1_000 + "s"); -// for (int i = 0; i < 10; i++) { -// for (int j = 0; j < 10; j++) { -// long s1 = System.currentTimeMillis(); -// parallelSum(items,10); -// long e1 = System.currentTimeMillis(); -// System.out.println((double)(e1-s1)/1_000 + "s"); -// } -// System.out.println("============================"); -// } + execute("sum", () -> sum(items, 10)); + execute("parallelSum", () -> parallelSum(items, 10)); } } From 67b3e7aa62b25ae7823acd553b81552dbbcc4c30 Mon Sep 17 00:00:00 2001 From: vector Date: Fri, 19 Oct 2018 18:58:30 +0800 Subject: [PATCH 14/14] update local --- .../chap11/standard/Resume.java | 43 +++++++++++ .../chap11/standard/StandardService.java | 77 +++++++++++++------ .../java/lambdasinaction/chap14/Currying.java | 5 ++ 3 files changed, 102 insertions(+), 23 deletions(-) diff --git a/src/main/java/lambdasinaction/chap11/standard/Resume.java b/src/main/java/lambdasinaction/chap11/standard/Resume.java index d633440e..306a6630 100644 --- a/src/main/java/lambdasinaction/chap11/standard/Resume.java +++ b/src/main/java/lambdasinaction/chap11/standard/Resume.java @@ -1,6 +1,9 @@ package lambdasinaction.chap11.standard; public class Resume { + + private StandardService standardService = new StandardService(); + private String company; private String school; @@ -9,6 +12,17 @@ public class Resume { private String title; + public Resume(String company, String school, String skill, String title) { + this.company = company; + this.school = school; + this.skill = skill; + this.title = title; + } + + public Resume() { + + } + public String getCompany() { return company; } @@ -41,4 +55,33 @@ public void setTitle(String title) { this.title = title; } + public Resume stadardCompany() { + this.company = standardService.stadardCompany(this.company); + return this; + } + + public Resume standardSchool() { + this.school = standardService.standardSchool(this.school); + return this; + } + + public Resume standardSkill() { + this.skill = standardService.standardSkill(this.skill); + return this; + } + + public Resume standardTitle() { + this.title = standardService.standardTitle(this.title); + return this; + } + + @Override + public String toString() { + return "Resume{" + + "company='" + company + '\'' + + ", school='" + school + '\'' + + ", skill='" + skill + '\'' + + ", title='" + title + '\'' + + '}'; + } } diff --git a/src/main/java/lambdasinaction/chap11/standard/StandardService.java b/src/main/java/lambdasinaction/chap11/standard/StandardService.java index 579d7378..84835757 100644 --- a/src/main/java/lambdasinaction/chap11/standard/StandardService.java +++ b/src/main/java/lambdasinaction/chap11/standard/StandardService.java @@ -3,10 +3,9 @@ import java.util.ArrayList; import java.util.List; import java.util.Random; -import java.util.concurrent.CompletableFuture; -import java.util.concurrent.Executor; -import java.util.concurrent.Executors; -import java.util.concurrent.ThreadFactory; +import java.util.concurrent.*; +import java.util.function.Supplier; +import java.util.stream.Collectors; public class StandardService { @@ -19,7 +18,6 @@ public Thread newThread(Runnable r) { } }); - public String stadardCompany(String company) { delay(100); return "standard " + company; @@ -53,36 +51,69 @@ public String buildTag(String com, String school, String skill, String title) { return com + school + skill + title + "tag"; } - public void oldFun(List resumes) { + public List oldFun(List resumes) { + List result = new ArrayList<>(); for (Resume resume : resumes) { - long start = System.nanoTime(); String company = this.stadardCompany(resume.getCompany()); String school= this.standardSchool(resume.getSchool()); String skill = this.standardSkill(resume.getSkill()); String title = this.standardTitle(resume.getTitle()); - System.out.println(this.buildTag(company, school, skill, title)); - long retrivalTime = ((System.nanoTime() - start) / 1_000_000); - System.out.println(retrivalTime); + result.add(new Resume(company, school, skill, title)); } + System.out.println(result); + return result; } - public void newFun(List resumes) { -// resumes.stream() -// .map(resume -> CompletableFuture.supplyAsync(() -> stadardCompany(resume.getCompany()), executor)) -// .map(task -> task -// .thenCompose(resume -> CompletableFuture.supplyAsync(()->standardSchool(resume.), executor))) -// .map(task -> task -// .thenCompose(resume -> CompletableFuture.supplyAsync(()->standardSchool(resume.gets), executor))); +// public List futureFun(List resumes) { +// List +// } + + public List newFun(List resumes) { + List> completableFutures = resumes.stream() + .map(resume -> CompletableFuture.supplyAsync(resume::stadardCompany, executor)) + .map(task -> task + .thenCompose(resume -> CompletableFuture.supplyAsync(resume::standardSchool, executor))) + .map(task -> task + .thenCompose(resume -> CompletableFuture.supplyAsync(resume::standardSkill, executor))) + .map(task -> task + .thenCompose(resume -> CompletableFuture.supplyAsync(resume::standardTitle, executor))) + .collect(Collectors.toList()); + List collect = completableFutures.stream().map(CompletableFuture::join).collect(Collectors.toList()); + System.out.println(collect); + return collect; + } + + public static void execute(String msg, Supplier> supplier) { + long s = System.nanoTime(); + supplier.get(); + long e = System.nanoTime(); + System.out.println(msg + " done in " + (e - s) / 1_000_000 + " mesc"); } public static void main(String[] args) { - Resume resume = new Resume(); - resume.setCompany("A"); - resume.setSchool("B"); - resume.setSkill("C"); - resume.setTitle("D"); + List resumes = new ArrayList(){{ + add(new Resume("A1", "B1", "C1", "D1")); + add(new Resume("A2", "B2", "C2", "D2")); + add(new Resume("A3", "B3", "C3", "D3")); + add(new Resume("A4", "B4", "C4", "D4")); + add(new Resume("A5", "B5", "C5", "D5")); + add(new Resume("A6", "B6", "C6", "D6")); + add(new Resume("A7", "B7", "C7", "D7")); + add(new Resume("A8", "B8", "C8", "D8")); + add(new Resume("A9", "B9", "C9", "D9")); + add(new Resume("A0", "B0", "C0", "D0")); + }}; + + List resumes2 = new ArrayList<>(); + + for (int i = 0; i < 1000; i++) { + resumes2.add(new Resume("A"+i, "B0", "C0", "D0")); + } + StandardService standardService = new StandardService(); -// standardService.oldFun(new ArrayList(){{add(resume)}}); +// execute("oldFun",()->standardService.oldFun(resumes) ); + execute("newFun",()->standardService.newFun(resumes) ); } + } diff --git a/src/main/java/lambdasinaction/chap14/Currying.java b/src/main/java/lambdasinaction/chap14/Currying.java index f17ac928..877f3373 100644 --- a/src/main/java/lambdasinaction/chap14/Currying.java +++ b/src/main/java/lambdasinaction/chap14/Currying.java @@ -22,6 +22,11 @@ static double converter(double x, double y, double z) { return x * y + z; } + + static DoubleUnaryOperator curriedConverter2(double f, double b) { + return operand -> operand * f + b; + } + static DoubleUnaryOperator curriedConverter(double y, double z) { return (double x) -> x * y + z; }