com.thoughtworks.proxy.toys.delegate

Class DelegatingInvoker<T>

java.lang.Object

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

All Implemented Interfaces:

Invoker, java.io.Serializable

Direct Known Subclasses:

HotSwappingInvoker, Pool.PoolingInvoker, PrivilegingInvoker

public class DelegatingInvoker<T>
extends java.lang.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

See Also:

HotSwappingInvoker, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private ObjectReference<T>	delegateReference
private DelegationMode	delegationMode
private java.util.Map<java.lang.reflect.Method,java.lang.reflect.Method>	methodCache
private ProxyFactory	proxyFactory
private static long	serialVersionUID

Constructor Summary

Constructors

Constructor and Description
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

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

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

methodCache

private transient java.util.Map<java.lang.reflect.Method,java.lang.reflect.Method> methodCache

proxyFactory

private ProxyFactory proxyFactory

delegateReference

private ObjectReference<T> delegateReference

delegationMode

private DelegationMode delegationMode

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:

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

java.lang.Throwable - if the invoked method has thrown.

delegate

protected T delegate()

Retrieve the delegated object in derived classes.

Returns:

the delegated object

getMethodToInvoke

protected java.lang.reflect.Method getMethodToInvoke(java.lang.reflect.Method method,
                                                     java.lang.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 java.lang.Object invokeOnDelegate(java.lang.reflect.Method method,
                                            java.lang.Object[] args)
                                     throws java.lang.reflect.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:

java.lang.reflect.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(java.lang.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 java.lang.Object

Since:

0.2

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

readObject

private void readObject(java.io.ObjectInputStream in)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException

Throws:

java.io.IOException

java.lang.ClassNotFoundException