001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.camel.spi; 018 019 import org.apache.camel.CamelContext; 020 import org.apache.camel.Processor; 021 import org.apache.camel.model.ProcessorDefinition; 022 023 /** 024 * The purpose of this interface is to allow an implementation to wrap 025 * processors in a route with interceptors. For example, a possible 026 * usecase is to gather performance statistics at the processor's level. 027 * <p/> 028 * Its <b>strongly</b> adviced to use an {@link org.apache.camel.AsyncProcessor} as the returned wrapped 029 * {@link Processor} which ensures the interceptor works well with the asynchronous routing engine. 030 * You can use the {@link org.apache.camel.processor.DelegateAsyncProcessor} to easily return an 031 * {@link org.apache.camel.AsyncProcessor} and override the 032 * {@link org.apache.camel.AsyncProcessor#process(org.apache.camel.Exchange, org.apache.camel.AsyncCallback)} to 033 * implement your interceptor logic. And just invoke the super method to <b>continue</b> routing. 034 * 035 * @version 036 */ 037 public interface InterceptStrategy { 038 039 /** 040 * This method is invoked by 041 * {@link ProcessorDefinition#wrapProcessor(RouteContext, Processor)} 042 * to give the implementor an opportunity to wrap the target processor 043 * in a route. 044 * <p/> 045 * <b>Important:</b> See the class javadoc for advice on letting interceptor be compatible with the 046 * asynchronous routing engine. 047 * 048 * @param context Camel context 049 * @param definition the model this interceptor represents 050 * @param target the processor to be wrapped 051 * @param nextTarget the next processor to be routed to 052 * @return processor wrapped with an interceptor or not wrapped. 053 * @throws Exception can be thrown 054 */ 055 Processor wrapProcessorInInterceptors(CamelContext context, ProcessorDefinition<?> definition, 056 Processor target, Processor nextTarget) throws Exception; 057 }