org.equilibriums.aop.utils.interceptor.delegate
Class DelegateInterceptor

java.lang.Object
  org.equilibriums.aop.utils.interceptor.delegate.DelegateInterceptor

All Implemented Interfaces:

org.aopalliance.aop.Advice, org.aopalliance.intercept.Interceptor, org.aopalliance.intercept.MethodInterceptor

public class DelegateInterceptor
extends Object
implements org.aopalliance.intercept.MethodInterceptor

Will delegate method calls this interceptor is configured for to specified delegates.

You can optionally override delegate's method to be called by specifying delegateMethodMap.

Return value from delegate calls are handled by first DelegateReturnValueHandler that will return true from its DelegateReturnValueHandler.supports(java.lang.Class, java.util.List) method. If no DelegateReturnValueHandler are specified will return null.

Here are some Design Pattern use cases that can be achieved by this interceptor without declaring any new type.

Delegate Pattern:

• Specify single delegate that has same method this interceptor is configured for.
• Configure proxy that is going to use this interceptor as described in Overview section of this Javadoc.

Composite Pattern:

• Specifiy one or more delegates that have same method this interceptor is configured for.
• Select appropriate ReturnValueHandler handlers depending on return value of the method you are intercepting. For void method you leave the handlers empty .
• Configure proxy that is going to use this interceptor as described in Overview section of this Javadoc.

For more on how to use this interceptor see Overview section of this Javadoc.

Author:

Tsolak Petrosian

Constructor Summary

DelegateInterceptor()

Method Summary

Map<Object,Method>	getDelegateMethodMap() Map where key is delegate and value is the method to be called by this interceptor instead of using invocation.getMethod() method.
List<DelegateReturnValueHandler>	getDelegateReturnValueHandlers()
List<Object>	getDelegates()
Object	invoke(org.aopalliance.intercept.MethodInvocation invocation)
void	setDelegateMethodMap(Map<Object,Method> delegateMethodMap)
void	setDelegateReturnValueHandlers(List<DelegateReturnValueHandler> delegateReturnValueHandlers)
void	setDelegates(List<Object> delegates)

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegateInterceptor

public DelegateInterceptor()

Method Detail

getDelegates

public List<Object> getDelegates()

setDelegates

public void setDelegates(List<Object> delegates)

getDelegateMethodMap

public Map<Object,Method> getDelegateMethodMap()

Map where key is delegate and value is the method to be called by this interceptor instead of using invocation.getMethod() method.

Returns:

setDelegateMethodMap

public void setDelegateMethodMap(Map<Object,Method> delegateMethodMap)

getDelegateReturnValueHandlers

public List<DelegateReturnValueHandler> getDelegateReturnValueHandlers()

setDelegateReturnValueHandlers

public void setDelegateReturnValueHandlers(List<DelegateReturnValueHandler> delegateReturnValueHandlers)

invoke

public Object invoke(org.aopalliance.intercept.MethodInvocation invocation)
              throws Throwable

Specified by:

invoke in interface org.aopalliance.intercept.MethodInterceptor

Throws:

Throwable