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.impl; 018 019 import java.util.HashMap; 020 import java.util.Map; 021 import java.util.Set; 022 import javax.activation.DataHandler; 023 024 import org.apache.camel.Exchange; 025 import org.apache.camel.util.MessageHelper; 026 027 /** 028 * The default implementation of {@link org.apache.camel.Message} 029 * 030 * @version $Revision: 789087 $ 031 */ 032 public class DefaultMessage extends MessageSupport { 033 private Map<String, Object> headers; 034 private Map<String, DataHandler> attachments; 035 036 @Override 037 public String toString() { 038 return MessageHelper.extractBodyForLogging(this); 039 } 040 041 public Object getHeader(String name) { 042 return getHeaders().get(name); 043 } 044 045 public <T> T getHeader(String name, Class<T> type) { 046 Object value = getHeader(name); 047 048 // eager same instance type test to avoid the overhead of invoking the type converter 049 // if already same type 050 if (type.isInstance(value)) { 051 return type.cast(value); 052 } 053 054 Exchange e = getExchange(); 055 if (e != null) { 056 return e.getContext().getTypeConverter().convertTo(type, e, value); 057 } else { 058 return (T) value; 059 } 060 } 061 062 public void setHeader(String name, Object value) { 063 if (headers == null) { 064 headers = createHeaders(); 065 } 066 headers.put(name, value); 067 } 068 069 public Object removeHeader(String name) { 070 if (headers != null) { 071 return headers.remove(name); 072 } else { 073 return null; 074 } 075 } 076 077 public Map<String, Object> getHeaders() { 078 if (headers == null) { 079 headers = createHeaders(); 080 } 081 return headers; 082 } 083 084 public void setHeaders(Map<String, Object> headers) { 085 this.headers = headers; 086 } 087 088 public DefaultMessage newInstance() { 089 return new DefaultMessage(); 090 } 091 092 /** 093 * A factory method to lazily create the headers to make it easy to create 094 * efficient Message implementations which only construct and populate the 095 * Map on demand 096 * 097 * @return return a newly constructed Map possibly containing headers from 098 * the underlying inbound transport 099 */ 100 protected Map<String, Object> createHeaders() { 101 Map<String, Object> map = new HashMap<String, Object>(); 102 populateInitialHeaders(map); 103 return map; 104 } 105 106 /** 107 * A strategy method populate the initial set of headers on an inbound 108 * message from an underlying binding 109 * 110 * @param map is the empty header map to populate 111 */ 112 protected void populateInitialHeaders(Map<String, Object> map) { 113 } 114 115 /** 116 * A factory method to lazily create the attachments to make it easy to 117 * create efficient Message implementations which only construct and 118 * populate the Map on demand 119 * 120 * @return return a newly constructed Map 121 */ 122 protected Map<String, DataHandler> createAttachments() { 123 Map<String, DataHandler> map = new HashMap<String, DataHandler>(); 124 populateInitialAttachments(map); 125 return map; 126 } 127 128 /** 129 * A strategy method populate the initial set of attachments on an inbound 130 * message from an underlying binding 131 * 132 * @param map is the empty attachment map to populate 133 */ 134 protected void populateInitialAttachments(Map<String, DataHandler> map) { 135 } 136 137 public void addAttachment(String id, DataHandler content) { 138 if (attachments == null) { 139 attachments = createAttachments(); 140 } 141 attachments.put(id, content); 142 } 143 144 public DataHandler getAttachment(String id) { 145 return getAttachments().get(id); 146 } 147 148 public Set<String> getAttachmentNames() { 149 if (attachments == null) { 150 attachments = createAttachments(); 151 } 152 return attachments.keySet(); 153 } 154 155 public void removeAttachment(String id) { 156 if (attachments != null && attachments.containsKey(id)) { 157 attachments.remove(id); 158 } 159 } 160 161 public Map<String, DataHandler> getAttachments() { 162 if (attachments == null) { 163 attachments = createAttachments(); 164 } 165 return attachments; 166 } 167 168 public void setAttachments(Map<String, DataHandler> attachments) { 169 this.attachments = attachments; 170 } 171 172 public boolean hasAttachments() { 173 if (attachments == null) { 174 attachments = createAttachments(); 175 } 176 return this.attachments != null && this.attachments.size() > 0; 177 } 178 179 /** 180 * Returns true if the headers have been mutated in some way 181 */ 182 protected boolean hasPopulatedHeaders() { 183 return headers != null; 184 } 185 186 public String createExchangeId() { 187 return null; 188 } 189 }