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

  • Constructor Details

    • ProxyGeneratorAdapter

      public ProxyGeneratorAdapter(Map<Object,Object> closureMap, Class requestedSuperClass, 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

    • isProxyHidden

      public boolean isProxyHidden()
      Diagnostic: true if this adapter's proxy was defined as a hidden nestmate (JEP 371). Not part of the stable user-facing proxy contract.
      Returns:
      true when the proxy class is hidden

    • visit

      public void visit(int version, int access, String name, String signature, String superName, String[] interfaces)
      Overrides:
      visit in class org.objectweb.asm.ClassVisitor

    • proxyName

      public String proxyName()
      Returns the proxy name used in the generated bytecode (internal form). This is also the name visible in stack traces for visible-class proxies.
      Returns:
      the proxy name

    • 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.