ConcurrentHashMap examples

Author: winterbe

src/com/winterbe/java8/samples/concurrent/ConcurrentHashMap1.java

@@ -9,20 +9,64 @@
 publicclassConcurrentHashMap1{
 
 publicstaticvoidmain(String[] args){
+System.out.println("Parallelism: " + ForkJoinPool.getCommonPoolParallelism());
+
 testForEach();
+testSearch();
+testReduce();
  }
 
-privatestaticvoidtestForEach(){
+privatestaticvoidtestReduce(){
 ConcurrentHashMap<String, String> map = newConcurrentHashMap<>();
 map.putIfAbsent("foo", "bar");
 map.putIfAbsent("han", "solo");
 map.putIfAbsent("r2", "d2");
 map.putIfAbsent("c3", "p0");
 
+Stringreduced = map.reduce(1, (key, value) -> key + "=" + value,
+ (s1, s2) -> s1 + ", " + s2);
 
-// map.forEach((key, value) -> System.out.printf("key: %s; value: %s\n", key, value));
+System.out.println(reduced);
+ }
 
-System.out.println("Parallelism: " + ForkJoinPool.getCommonPoolParallelism());
+privatestaticvoidtestSearch(){
+ConcurrentHashMap<String, String> map = newConcurrentHashMap<>();
+map.putIfAbsent("foo", "bar");
+map.putIfAbsent("han", "solo");
+map.putIfAbsent("r2", "d2");
+map.putIfAbsent("c3", "p0");
+
+System.out.println("\nsearch()\n");
+
+Stringresult1 = map.search(1, (key, value) ->{
+System.out.println(Thread.currentThread().getName());
+if (key.equals("foo") && value.equals("bar")){
+return"foobar";
+ }
+returnnull;
+ });
+
+System.out.println(result1);
+
+System.out.println("\nsearchValues()\n");
+
+Stringresult2 = map.searchValues(1, value ->{
+System.out.println(Thread.currentThread().getName());
+if (value.length() > 3){
+returnvalue;
+ }
+returnnull;
+ });
+
+System.out.println(result2);
+ }
+
+privatestaticvoidtestForEach(){
+ConcurrentHashMap<String, String> map = newConcurrentHashMap<>();
+map.putIfAbsent("foo", "bar");
+map.putIfAbsent("han", "solo");
+map.putIfAbsent("r2", "d2");
+map.putIfAbsent("c3", "p0");
 
 map.forEach(1, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));
 // map.forEach(5, (key, value) -> System.out.printf("key: %s; value: %s; thread: %s\n", key, value, Thread.currentThread().getName()));