Package org.codehaus.groovy.runtime

Class ProxyGeneratorAdapter

java.lang.Object

org.objectweb.asm.ClassVisitor

org.codehaus.groovy.runtime.ProxyGeneratorAdapter

public class ProxyGeneratorAdapter
extends org.objectweb.asm.ClassVisitor

A proxy generator responsible for mapping a map of closures to a class implementing a list of interfaces. For example, the following code:

     abstract class Foo {
         abstract void bar();
         abstract void baz();
     }
     def dyn = [bar: { println 'hello' }, baz: { println 'world'}] as Foo
 

will generate a proxy class which extends class Foo and delegates method calls to the provided closures. The generated proxy implements the GroovyObject interface. Additionally, this proxy generator supports delegation to another object. In that case, if a method is defined both in the closure map and the delegate, the version from the map is preferred. This allows overriding methods from delegates with ease. Internally, the proxy generator makes use of ASM to generate bytecode, for improved performance as compared to the legacy proxy generation mechanism which made use of string templates.

Since:

2.0.0

Field Summary

Fields inherited from class org.objectweb.asm.ClassVisitor

api, cv

Constructor Summary

Constructors

Constructor	Description
ProxyGeneratorAdapter(Map<Object,Object> closureMap, Class superClass, Class[] interfaces, ClassLoader proxyLoader, boolean emptyBody, Class delegateClass)	Construct a proxy generator.

Method Summary

Modifier and Type	Method	Description
GroovyObject	delegatingProxy(Object delegate, Map<Object,Object> map, Object... constructorArgs)
static Closure	ensureClosure(Object o)	Ensures that the provided object is wrapped into a closure if it's not a closure.
protected org.objectweb.asm.MethodVisitor	makeDelegateCall(String name, String desc, String signature, String[] exceptions, int accessFlags)	Generate a call to the delegate object.
protected org.objectweb.asm.MethodVisitor	makeDelegateToClosureCall(String name, String desc, String signature, String[] exceptions, int accessFlags)
GroovyObject	proxy(Map<Object,Object> map, Object... constructorArgs)
void	visit(int version, int access, String name, String signature, String superName, String[] interfaces)
org.objectweb.asm.MethodVisitor	visitMethod(int access, String name, String desc, String signature, String[] exceptions)

Methods inherited from class org.objectweb.asm.ClassVisitor

getDelegate, visitAnnotation, visitAttribute, visitEnd, visitField, visitInnerClass, visitModule, visitNestHost, visitNestMember, visitOuterClass, visitPermittedSubclass, visitRecordComponent, visitSource, visitTypeAnnotation

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ProxyGeneratorAdapter

public ProxyGeneratorAdapter(Map<Object,Object> closureMap,
 Class superClass,
 Class[] interfaces,
 ClassLoader proxyLoader,
 boolean emptyBody,
 Class delegateClass)

Construct a proxy generator. This generator is used when we need to create a proxy object for a class or an interface given a map of closures.

Parameters:

closureMap - the delegates implementations

superClass - corresponding to the superclass class visitor

interfaces - extra interfaces the proxy should implement

proxyLoader - the class loader which should be used to load the generated proxy

delegateClass - if not null, generate a delegate field with the corresponding class

emptyBody - if set to true, the unimplemented abstract methods will receive an empty body instead of throwing an UnsupportedOperationException.

Method Details

visit

public void visit(int version,
 int access,
 String name,
 String signature,
 String superName,
 String[] interfaces)

Overrides:

visit in class org.objectweb.asm.ClassVisitor

visitMethod

public org.objectweb.asm.MethodVisitor visitMethod(int access,
 String name,
 String desc,
 String signature,
 String[] exceptions)

Overrides:

visitMethod in class org.objectweb.asm.ClassVisitor

makeDelegateCall

protected org.objectweb.asm.MethodVisitor makeDelegateCall(String name,
 String desc,
 String signature,
 String[] exceptions,
 int accessFlags)

Generate a call to the delegate object.

makeDelegateToClosureCall

protected org.objectweb.asm.MethodVisitor makeDelegateToClosureCall(String name,
 String desc,
 String signature,
 String[] exceptions,
 int accessFlags)

proxy

public GroovyObject proxy(Map<Object,Object> map,
 Object... constructorArgs)

delegatingProxy

public GroovyObject delegatingProxy(Object delegate,
 Map<Object,Object> map,
 Object... constructorArgs)

ensureClosure

public static Closure ensureClosure(Object o)

Ensures that the provided object is wrapped into a closure if it's not a closure. Do not trust IDEs, this method is used in bytecode.