com.thoughtworks.proxy.toys.delegate
Class DelegatingInvoker<T>

java.lang.Object
  com.thoughtworks.proxy.toys.delegate.DelegatingInvoker<T>

All Implemented Interfaces:

Invoker, Serializable

Direct Known Subclasses:

HotSwappingInvoker, Pool.PoolingInvoker, PrivilegingInvoker

public class DelegatingInvoker<T>
extends Object
implements Invoker

Invoker that delegates method calls to an object.

This forms the basis of many other proxy toys. The delegation behavior was factored out of HotSwappingInvoker.

Since:

0.1

Author:

Aslak Hellesøy, Paul Hammant, Dan North, Jörg Schaible

See Also:

HotSwappingInvoker, Serialized Form

Constructor Summary

DelegatingInvoker(ProxyFactory proxyFactory, ObjectReference<T> delegateReference, DelegationMode delegationMode)
Construct a DelegatingInvoker.

DelegatingInvoker(T delegate)
Construct a DelegatingInvoker with a StandardProxyFactory and DelegationMode.SIGNATURE.

Method Summary

protected T	delegate() Retrieve the delegated object in derived classes.
boolean	equals(Object obj) Compares a DelegatingInvoker with another one for equality.
protected ObjectReference<T>	getDelegateReference() Retrieve the ObjectReference of the delegate.
protected Method	getMethodToInvoke(Method method, Object[] args) Lookup a matching method.
protected ProxyFactory	getProxyFactory() Retrieve the ProxyFactory to use.
int	hashCode()
Object	invoke(Object proxy, Method method, Object[] args) Invocation of a method of the proxied object.
protected Object	invokeOnDelegate(Method method, Object[] args) Invoke the given method on the delegate.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingInvoker

public DelegatingInvoker(ProxyFactory proxyFactory,
                         ObjectReference<T> delegateReference,
                         DelegationMode delegationMode)

Construct a DelegatingInvoker.

Parameters:

proxyFactory - the ProxyFactory to use

delegateReference - the ObjectReference of the delegate

delegationMode - one of the delegation modes

Throws:

IllegalArgumentException - if the delegationMode is not one of the predefined constants of Delegating

Since:

1.0

DelegatingInvoker

public DelegatingInvoker(T delegate)

Construct a DelegatingInvoker with a StandardProxyFactory and DelegationMode.SIGNATURE.

Parameters:

delegate - the delegated object

Since:

0.1

Method Detail

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable

Description copied from interface: Invoker

Invocation of a method of the proxied object.

Specified by:

invoke in interface Invoker

Parameters:

proxy - the proxy instance.

method - the method to invoke.

args - the arguments of the method.

Returns:

the result of the invoked method.

Throws:

Throwable - if the invoked method has thrown.

delegate

protected T delegate()

Retrieve the delegated object in derived classes.

Returns:

the delegated object

getMethodToInvoke

protected Method getMethodToInvoke(Method method,
                                   Object[] args)

Lookup a matching method. The lookup will only be done once for every method called on the proxy.

Parameters:

method - the invoked method on the proxy

args - the arguments for the invocation

Returns:

the matching method

Throws:

DelegationException - if no matching method can be found

Since:

0.2

invokeOnDelegate

protected Object invokeOnDelegate(Method method,
                                  Object[] args)
                           throws InvocationTargetException

Invoke the given method on the delegate.

Parameters:

method - the method to invoke

args - the arguments for the invocation

Returns:

the method's result

Throws:

InvocationTargetException - if the invoked method throws any exception

Since:

0.1

getDelegateReference

protected ObjectReference<T> getDelegateReference()

Retrieve the ObjectReference of the delegate.

Returns:

the reference of the delegate

Since:

0.2

getProxyFactory

protected ProxyFactory getProxyFactory()

Retrieve the ProxyFactory to use.

Returns:

the ProxyFactory

Since:

0.2

equals

public boolean equals(Object obj)

Compares a DelegatingInvoker with another one for equality. Two DelegatingInvoker are equal, if they have both the same delegation mode and their delegees are equal.

Overrides:

equals in class Object

Since:

0.2

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Overrides:

hashCode in class Object