Package com.google.common.reflect

Class AbstractInvocationHandler

com.google.common.reflect.AbstractInvocationHandler

All Implemented Interfaces:

@Beta
public abstract class AbstractInvocationHandler
extends 
implements 

Abstract implementation of that handles , and . 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

Author:

Ben Yu

Constructor Summary

Constructors

Constructor	Description
AbstractInvocationHandler()

Method Summary

Modifier and Type	Method	Description
boolean	obj)	By default delegates to so instances are only equal if they are identical.
protected abstract	proxy, method, [] 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 , and .
int	hashCode()	By default delegates to .
	proxy, method, [] args)	Processes a method invocation on a proxy instance and returns the result.
	toString()	By default delegates to .

Methods inherited from class java.lang.

, , , , , , ,

Constructor Detail

AbstractInvocationHandler

public AbstractInvocationHandler()

Method Detail

invoke

public final   proxy,
                            method,
                             [] args)
                    throws 

Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.

• 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 of argument
• other method calls are dispatched to handleInvocation(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]).

Specified by:

in interface

Parameters:

proxy - the proxy instance that the method was invoked on

method - the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.

args - an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

Returns:

the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the interface method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.

Throws:

- the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the interface method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the interface method, then an containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

See Also:

handleInvocation

protected abstract   proxy,
                                            method,
                                           [] args)
                                    throws 

invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]) delegates to this method upon any method invocation on the proxy instance, except , and . 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:

equals

public boolean  obj)

By default delegates to 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 of argument

Subclasses can override this method to provide custom equality.

Overrides:

in class

Parameters:

obj - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

,

hashCode

public int hashCode()

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

Overrides:

in class

Returns:

a hash code value for this object.

See Also:

,

toString

public  toString()

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

Overrides:

in class

Returns:

a string representation of the object.