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 */ 017package org.apache.camel.spi; 018 019import org.apache.camel.CamelContext; 020import org.apache.camel.Processor; 021import 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 * <b>Important: </b> This SPI is not intended to be used by Camel end users - do NOT use this. 029 * <p/> 030 * Its <b>strongly</b> adviced to use an {@link org.apache.camel.AsyncProcessor} as the returned wrapped 031 * {@link Processor} which ensures the interceptor works well with the asynchronous routing engine. 032 * You can use the {@link org.apache.camel.processor.DelegateAsyncProcessor} to easily return an 033 * {@link org.apache.camel.AsyncProcessor} and override the 034 * {@link org.apache.camel.AsyncProcessor#process(org.apache.camel.Exchange, org.apache.camel.AsyncCallback)} to 035 * implement your interceptor logic. And just invoke the super method to <b>continue</b> routing. 036 * 037 * @version 038 */ 039public interface InterceptStrategy { 040 041 // TODO: Camel 3.0 make this an internal API 042 043 /** 044 * This method is invoked by 045 * {@link ProcessorDefinition#wrapProcessor(RouteContext, Processor)} 046 * to give the implementor an opportunity to wrap the target processor 047 * in a route. 048 * <p/> 049 * <b>Important:</b> See the class javadoc for advice on letting interceptor be compatible with the 050 * asynchronous routing engine. 051 * 052 * @param context Camel context 053 * @param definition the model this interceptor represents 054 * @param target the processor to be wrapped 055 * @param nextTarget the next processor to be routed to 056 * @return processor wrapped with an interceptor or not wrapped. 057 * @throws Exception can be thrown 058 */ 059 Processor wrapProcessorInInterceptors(CamelContext context, ProcessorDefinition<?> definition, 060 Processor target, Processor nextTarget) throws Exception; 061}