org.aopalliance.intercept

Interface ConstructorInterceptor

All Superinterfaces:

Advice, Interceptor

public interface ConstructorInterceptor
extends Interceptor

Intercepts the construction of a new object.

The user should implement the construct(ConstructorInvocation) method to modify the original behavior. E.g. the following class implements a singleton interceptor (allows only one unique instance for the intercepted class):

 class DebuggingInterceptor implements ConstructorInterceptor {
   Object instance=null;

   Object construct(ConstructorInvocation i) throws Throwable {
     if(instance==null) {
       return instance=i.proceed();
     } else {
       throw new Exception("singleton does not allow multiple instance");
     }
   }
 }
 

Author:

Rod Johnson

Method Summary

Modifier and Type	Method and Description
java.lang.Object	construct(ConstructorInvocation invocation) Implement this method to perform extra treatments before and after the construction of a new object.

Method Detail

construct

java.lang.Object construct(ConstructorInvocation invocation)
                    throws java.lang.Throwable

Implement this method to perform extra treatments before and after the construction of a new object. Polite implementations would certainly like to invoke Joinpoint.proceed().

Parameters:

invocation - the construction joinpoint

Returns:

the newly created object, which is also the result of the call to Joinpoint.proceed(); might be replaced by the interceptor

Throws:

java.lang.Throwable - if the interceptors or the target object throws an exception