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.Processor; 020import org.apache.camel.model.ProcessorDefinition; 021 022/** 023 * A strategy capable of applying interceptors to a processor. 024 * <p/> 025 * Its <b>strongly</b> advised to use an {@link org.apache.camel.AsyncProcessor} as the returned wrapped 026 * {@link Processor} which ensures the policy works well with the asynchronous routing engine. 027 * You can use the {@link org.apache.camel.processor.DelegateAsyncProcessor} to easily return an 028 * {@link org.apache.camel.AsyncProcessor} and override the 029 * {@link org.apache.camel.AsyncProcessor#process(org.apache.camel.Exchange, org.apache.camel.AsyncCallback)} to 030 * implement your interceptor logic. And just invoke the super method to <b>continue</b> routing. 031 * <p/> 032 * Mind that not all frameworks supports asynchronous routing, for example some transaction managers, such as 033 * Spring Transaction uses the current thread to store state of the transaction, and thus can't transfer this 034 * state to other threads when routing continues asynchronously. 035 * 036 * @version 037 */ 038public interface Policy { 039 040 /** 041 * Hook invoked before the wrap. 042 * <p/> 043 * This allows you to do any custom logic before the processor is wrapped. For example to 044 * manipulate the {@link org.apache.camel.model.ProcessorDefinition definiton} 045 * 046 * @param routeContext the route context 047 * @param definition the processor definition 048 */ 049 void beforeWrap(RouteContext routeContext, ProcessorDefinition<?> definition); 050 051 /** 052 * Wraps any applicable interceptors around the given processor. 053 * 054 * @param routeContext the route context 055 * @param processor the processor to be intercepted 056 * @return either the original processor or a processor wrapped in one or more processors 057 */ 058 Processor wrap(RouteContext routeContext, Processor processor); 059}