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. For example, 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	Description
Object	construct(ConstructorInvocation invocation)	Implement this method to perform extra treatments before and after the construction of a new object.

Method Details

construct

Object construct(ConstructorInvocation invocation)
          throws 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:

Throwable - if the interceptors or the target object throws an exception