Please use the ReflectASM discussion group for support.

ReflectASM is a very small Java library that provides high performance reflection by using code generation. An access class is generated to set/get fields, call methods, or create a new instance. The access class uses bytecode rather than Java's reflection, so it is much faster. It can also access primitive fields via bytecode to avoid boxing.

The source code for these benchmarks is included in the project. The above charts were generated on Oracle's Java 7u3, server VM.

To use reflectasm with maven, please use the following snippet in your pom.xml

 <dependency> <groupId>com.esotericsoftware</groupId> <artifactId>reflectasm</artifactId> <version>1.11.9</version> </dependency>

Method reflection with ReflectASM:

SomeClasssomeObject = ... MethodAccessaccess = MethodAccess.get(SomeClass.class); access.invoke(someObject, "setName", "Awesome McLovin"); Stringname = (String)access.invoke(someObject, "getName");

Field reflection with ReflectASM:

SomeClasssomeObject = ... FieldAccessaccess = FieldAccess.get(SomeClass.class); access.set(someObject, "name", "Awesome McLovin"); Stringname = (String)access.get(someObject, "name");

Constructor reflection with ReflectASM:

ConstructorAccess<SomeClass> access = ConstructorAccess.get(SomeClass.class); SomeClasssomeObject = access.newInstance();

For maximum performance when methods or fields are accessed repeatedly, the method or field index should be used instead of the name:

SomeClasssomeObject = ... MethodAccessaccess = MethodAccess.get(SomeClass.class); intaddNameIndex = access.getIndex("addName"); for (Stringname : names) access.invoke(someObject, addNameIndex, "Awesome McLovin");

Iterate all fields:

FieldAccessaccess = FieldAccess.get(SomeClass.class); for(inti = 0, n = access.getFieldCount(); i < n; i++){access.set(instanceObject, i, valueToPut)}

ReflectASM can always access public members. An attempt is made to define access classes in the same classloader (using setAccessible) and package as the accessed class. If the security manager allows setAccessible to succeed, then protected and default access (package private) members can be accessed. If setAccessible fails, no exception is thrown, but only public members can be accessed. Private members can never be accessed.

Stack traces when using ReflectASM are a bit cleaner. Here is Java's reflection calling a method that throws a RuntimeException:

Exception in thread "main" java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.example.SomeCallingCode.doit(SomeCallingCode.java:22) Caused by: java.lang.RuntimeException at com.example.SomeClass.someMethod(SomeClass.java:48) ... 5 more 

Here is the same but when ReflectASM is used:

Exception in thread "main" java.lang.RuntimeException at com.example.SomeClass.someMethod(SomeClass.java:48) at com.example.SomeClassMethodAccess.invoke(Unknown Source) at com.example.SomeCallingCode.doit(SomeCallingCode.java:22) 

If ReflectASM is used to invoke code that throws a checked exception, the checked exception is thrown. Because it is a compilation error to use try/catch with a checked exception around code that doesn't declare that exception as being thrown, you must catch Exception if you care about catching a checked exception in code you invoke with ReflectASM.