Package com.google.common.reflect

Class AbstractInvocationHandler

java.lang.Object

com.google.common.reflect.AbstractInvocationHandler

All Implemented Interfaces:

java.lang.reflect.InvocationHandler

Direct Known Subclasses:

DummyProxy.DummyHandler, ForwardingWrapperTester.InteractionTester, FreshValueGenerator.FreshInvocationHandler

@Beta
public abstract class AbstractInvocationHandler
extends java.lang.Object
implements java.lang.reflect.InvocationHandler

Abstract implementation of InvocationHandler that handles Object.equals(java.lang.Object), Object.hashCode() and Object.toString(). For example:

 class Unsupported extends AbstractInvocationHandler {
   protected Object handleInvocation(Object proxy, Method method, Object[] args) {
     throw new UnsupportedOperationException();
   }
 }

 CharSequence unsupported = Reflection.newProxy(CharSequence.class, new Unsupported());
 

Since:

12.0

Field Summary

Fields

Modifier and Type	Field	Description
private static java.lang.Object[]	NO_ARGS

Constructor Summary

Constructors

Constructor	Description
AbstractInvocationHandler()

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object obj)	By default delegates to Object.equals(java.lang.Object) so instances are only equal if they are identical.
protected abstract java.lang.Object	handleInvocation(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)	invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]) delegates to this method upon any method invocation on the proxy instance, except Object.equals(java.lang.Object), Object.hashCode() and Object.toString().
int	hashCode()	By default delegates to Object.hashCode().
java.lang.Object	invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)	proxy.hashCode() delegates to hashCode() proxy.toString() delegates to toString() proxy.equals(argument) returns true if: proxy and argument are of the same type and equals(java.lang.Object) returns true for the InvocationHandler of argument other method calls are dispatched to handleInvocation(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]).
private static boolean	isProxyOfSameInterfaces(java.lang.Object arg, java.lang.Class<?> proxyClass)
java.lang.String	toString()	By default delegates to Object.toString().

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_ARGS

private static final java.lang.Object[] NO_ARGS

Constructor Detail

AbstractInvocationHandler

public AbstractInvocationHandler()

Method Detail

invoke

public final java.lang.Object invoke(java.lang.Object proxy,
                                     java.lang.reflect.Method method,
                                     java.lang.Object[] args)
                              throws java.lang.Throwable

• proxy.hashCode() delegates to hashCode()
• proxy.toString() delegates to toString()
• proxy.equals(argument) returns true if:
  • proxy and argument are of the same type
  • and equals(java.lang.Object) returns true for the InvocationHandler of argument
• other method calls are dispatched to handleInvocation(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]).

Specified by:

invoke in interface java.lang.reflect.InvocationHandler

Throws:

java.lang.Throwable

handleInvocation

protected abstract java.lang.Object handleInvocation(java.lang.Object proxy,
                                                     java.lang.reflect.Method method,
                                                     java.lang.Object[] args)
                                              throws java.lang.Throwable

invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]) delegates to this method upon any method invocation on the proxy instance, except Object.equals(java.lang.Object), Object.hashCode() and Object.toString(). The result will be returned as the proxied method's return value.

Unlike invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]), args will never be null. When the method has no parameter, an empty array is passed in.

Throws:

java.lang.Throwable

equals

public boolean equals(java.lang.Object obj)

By default delegates to Object.equals(java.lang.Object) so instances are only equal if they are identical. proxy.equals(argument) returns true if:

• proxy and argument are of the same type
• and this method returns true for the InvocationHandler of argument

Subclasses can override this method to provide custom equality.

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

By default delegates to Object.hashCode(). The dynamic proxies' hashCode() will delegate to this method. Subclasses can override this method to provide custom equality.

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

By default delegates to Object.toString(). The dynamic proxies' toString() will delegate to this method. Subclasses can override this method to provide custom string representation for the proxies.

Overrides:

toString in class java.lang.Object

isProxyOfSameInterfaces

private static boolean isProxyOfSameInterfaces(java.lang.Object arg,
                                               java.lang.Class<?> proxyClass)