/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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package org.aopalliance.intercept;

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
/** * Intercepts the construction of a new object. * * <p>The user should implement the {@link * #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): * * <pre class=code> * 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"); * } * } * } * </pre> * * @author Rod Johnson */
public interface ConstructorInterceptor extends Interceptor {
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().
Params:
  • invocation – the construction joinpoint
Throws:
  • Throwable – if the interceptors or the target object throws an exception
Returns:the newly created object, which is also the result of the call to Joinpoint.proceed(); might be replaced by the interceptor
/** * Implement this method to perform extra treatments before and * after the construction of a new object. Polite implementations * would certainly like to invoke {@link Joinpoint#proceed()}. * @param invocation the construction joinpoint * @return the newly created object, which is also the result of * the call to {@link Joinpoint#proceed()}; might be replaced by * the interceptor * @throws Throwable if the interceptors or the target object * throws an exception */
Object construct(ConstructorInvocation invocation) throws Throwable; }