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.processor.interceptor; 018 019 import org.apache.camel.Exchange; 020 import org.apache.camel.Processor; 021 import org.apache.camel.model.ProcessorDefinition; 022 023 /** 024 * A handler which reacts on trace events. 025 */ 026 public interface TraceEventHandler { 027 028 /** 029 * Event called when an {@link Exchange} is about to be processed 030 * <p/> 031 * This event is only called if trace out has been disabled (which it is by default). 032 * <p/> 033 * This method is for coarse grained tracing, where as the the other two methods is for fine grained 034 * with in and event events. 035 * 036 * @param node the current node 037 * @param target the current processor being invoked 038 * @param traceInterceptor the trace interceptor 039 * @param exchange the current exchange 040 * @throws Exception is thrown if an error occurred during tracing 041 */ 042 void traceExchange(ProcessorDefinition<?> node, Processor target, TraceInterceptor traceInterceptor, Exchange exchange) throws Exception; 043 044 /** 045 * Event called when an {@link Exchange} is about to be processed (in) 046 * <p/> 047 * This event is only called if trace out has been enabled. 048 * 049 * @param node the current node 050 * @param target the current processor being invoked 051 * @param traceInterceptor the trace interceptor 052 * @param exchange the current exchange 053 * @return an optional return object to pass in the <tt>traceEventOut</tt> method. 054 * @throws Exception is thrown if an error occurred during tracing 055 */ 056 Object traceExchangeIn(ProcessorDefinition<?> node, Processor target, TraceInterceptor traceInterceptor, Exchange exchange) throws Exception; 057 058 /** 059 * Event called when an {@link Exchange} has been processed (out) 060 * <p/> 061 * This event is only called if trace out has been enabled. 062 * 063 * @param node the current node 064 * @param target the current processor being invoked 065 * @param traceInterceptor the trace interceptor 066 * @param exchange the current exchange (contains exception if the processing failed with an exception) 067 * @param traceState the optional object which was returned from the <tt>traceEventIn</tt> method. 068 * @throws Exception is thrown if an error occurred during tracing 069 */ 070 void traceExchangeOut(ProcessorDefinition<?> node, Processor target, TraceInterceptor traceInterceptor, Exchange exchange, Object traceState) throws Exception; 071 072 }