/* * 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 * limitations under the License. */ package org.aopalliance.intercept; import org.aopalliance.aop.Advice; /** * This interface represents a generic interceptor. * *

A generic interceptor can intercept runtime events that occur * within a base program. Those events are materialized by (reified * in) joinpoints. Runtime joinpoints can be invocations, field * access, exceptions... * *

This interface is not used directly. Use the sub-interfaces * to intercept specific events. For instance, the following class * implements some specific interceptors in order to implement a * debugger: * *

 * class DebuggingInterceptor implements MethodInterceptor, 
 *     ConstructorInterceptor, FieldInterceptor {
 *
 *   Object invoke(MethodInvocation i) throws Throwable {
 *     debug(i.getMethod(), i.getThis(), i.getArgs());
 *     return i.proceed();
 *   }
 *
 *   Object construct(ConstructorInvocation i) throws Throwable {
 *     debug(i.getConstructor(), i.getThis(), i.getArgs());
 *     return i.proceed();
 *   }
 * 
 *   Object get(FieldAccess fa) throws Throwable {
 *     debug(fa.getField(), fa.getThis(), null);
 *     return fa.proceed();
 *   }
 *
 *   Object set(FieldAccess fa) throws Throwable {
 *     debug(fa.getField(), fa.getThis(), fa.getValueToSet());
 *     return fa.proceed();
 *   }
 *
 *   void debug(AccessibleObject ao, Object this, Object value) {
 *     ...
 *   }
 * }
 * 
* * @author Rod Johnson * @see Joinpoint */ public interface Interceptor extends Advice { }