| 提交 | 用户 | age | ||
| a6a76f | 1 | /** |
| F | 2 | * |
| 3 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
| 4 | * contributor license agreements. See the NOTICE file distributed with | |
| 5 | * this work for additional information regarding copyright ownership. | |
| 6 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
| 7 | * (the "License"); you may not use this file except in compliance with | |
| 8 | * the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, software | |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 15 | * See the License for the specific language governing permissions and | |
| 16 | * limitations under the License. | |
| 17 | */ | |
| 18 | ||
| 19 | // AMQ Ajax handler | |
| 20 | // This class provides the main API for using the Ajax features of AMQ. It | |
| 21 | // allows JMS messages to be sent and received from javascript when used | |
| 22 | // with the org.apache.activemq.web.MessageListenerServlet. | |
| 23 | // | |
| 24 | // This version of the file provides an adapter interface for the jquery library | |
| 25 | // and a namespace for the Javascript file, private/public variables and | |
| 26 | // methods, and other scripting niceties. -- jim cook 2007/08/28 | |
| 27 | ||
| 28 | var org = org || {}; | |
| 29 | org.activemq = org.activemq || {}; | |
| 30 | ||
| 31 | org.activemq.Amq = function() { | |
| 32 | var connectStatusHandler; | |
| 33 | ||
| 34 | // Just a shortcut to eliminate some redundant typing. | |
| 35 | var adapter = org.activemq.AmqAdapter; | |
| 36 | ||
| 37 | if (typeof adapter == 'undefined') { | |
| 38 | throw 'An org.activemq.AmqAdapter must be declared before the amq.js script file.' | |
| 39 | } | |
| 40 | ||
| 41 | // The URI of the AjaxServlet. | |
| 42 | var uri; | |
| 43 | ||
| 44 | // The number of seconds that the long-polling socket will stay connected. | |
| 45 | // Best to keep this to a value less than one minute. | |
| 46 | var timeout; | |
| 47 | ||
| 48 | // Poll delay. if set to positive integer, this is the time to wait in ms | |
| 49 | // before sending the next poll after the last completes. | |
| 50 | var pollDelay; | |
| 51 | ||
| 52 | // Inidicates whether logging is active or not. Not by default. | |
| 53 | var logging = false; | |
| 54 | ||
| 55 | // 5 second delay if an error occurs during poll. This could be due to | |
| 56 | // server capacity problems or a timeout condition. | |
| 57 | var pollErrorDelay = 5000; | |
| 58 | ||
| 59 | // Map of handlers that will respond to message receipts. The id used during | |
| 60 | // addListener(id, destination, handler) is used to key the callback | |
| 61 | // handler. | |
| 62 | var messageHandlers = {}; | |
| 63 | ||
| 64 | // Indicates whether an AJAX post call is in progress. | |
| 65 | var batchInProgress = false; | |
| 66 | ||
| 67 | // A collection of pending messages that accumulate when an AJAX call is in | |
| 68 | // progress. These messages will be delivered as soon as the current call | |
| 69 | // completes. The array contains objects in the format { destination, | |
| 70 | // message, messageType }. | |
| 71 | var messageQueue = []; | |
| 72 | ||
| 73 | // String to distinguish this client from others sharing the same session. | |
| 74 | // This can occur when multiple browser windows or tabs using amq.js simultaneously. | |
| 75 | // All windows share the same JESSIONID, but need to consume messages independently. | |
| 76 | var clientId = null; | |
| 77 | ||
| 78 | /** | |
| 79 | * Iterate over the returned XML and for each message in the response, | |
| 80 | * invoke the handler with the matching id. | |
| 81 | */ | |
| 82 | var messageHandler = function(data) { | |
| 83 | var response = data.getElementsByTagName("ajax-response"); | |
| 84 | if (response != null && response.length == 1) { | |
| 85 | connectStatusHandler(true); | |
| 86 | var responses = response[0].childNodes; // <response> | |
| 87 | for (var i = 0; i < responses.length; i++) { | |
| 88 | var responseElement = responses[i]; | |
| 89 | ||
| 90 | // only process nodes of type element..... | |
| 91 | if (responseElement.nodeType != 1) continue; | |
| 92 | ||
| 93 | var id = responseElement.getAttribute('id'); | |
| 94 | ||
| 95 | var handler = messageHandlers[id]; | |
| 96 | ||
| 97 | if (logging && handler == null) { | |
| 98 | adapter.log('No handler found to match message with id = ' + id); | |
| 99 | continue; | |
| 100 | } | |
| 101 | ||
| 102 | // Loop thru and handle each <message> | |
| 103 | for (var j = 0; j < responseElement.childNodes.length; j++) { | |
| 104 | handler(responseElement.childNodes[j]); | |
| 105 | } | |
| 106 | } | |
| 107 | } | |
| 108 | }; | |
| 109 | ||
| 110 | var errorHandler = function(xhr, status, ex) { | |
| 111 | connectStatusHandler(false); | |
| 112 | if (logging) adapter.log('Error occurred in ajax call. HTTP result: ' + | |
| 113 | xhr.status + ', status: ' + status); | |
| 114 | } | |
| 115 | ||
| 116 | var pollErrorHandler = function(xhr, status, ex) { | |
| 117 | connectStatusHandler(false); | |
| 118 | if (status === 'error' && xhr.status === 0) { | |
| 119 | if (logging) adapter.log('Server connection dropped.'); | |
| 120 | setTimeout(function() { sendPoll(); }, pollErrorDelay); | |
| 121 | return; | |
| 122 | } | |
| 123 | if (logging) adapter.log('Error occurred in poll. HTTP result: ' + | |
| 124 | xhr.status + ', status: ' + status); | |
| 125 | setTimeout(function() { sendPoll(); }, pollErrorDelay); | |
| 126 | } | |
| 127 | ||
| 128 | var pollHandler = function(data) { | |
| 129 | try { | |
| 130 | messageHandler(data); | |
| 131 | } catch(e) { | |
| 132 | if (logging) adapter.log('Exception in the poll handler: ' + data, e); | |
| 133 | throw(e); | |
| 134 | } finally { | |
| 135 | setTimeout(sendPoll, pollDelay); | |
| 136 | } | |
| 137 | }; | |
| 138 | ||
| 139 | var sendPoll = function() { | |
| 140 | // Workaround IE6 bug where it caches the response | |
| 141 | // Generate a unique query string with date and random | |
| 142 | var now = new Date(); | |
| 143 | var data = 'timeout=' + timeout * 1000 | |
| 144 | + '&d=' + now.getTime() | |
| 145 | + '&r=' + Math.random(); | |
| 146 | var options = { method: 'get', | |
| 147 | data: addClientId( data ), | |
| 148 | success: pollHandler, | |
| 149 | error: pollErrorHandler}; | |
| 150 | adapter.ajax(uri, options); | |
| 151 | }; | |
| 152 | ||
| 153 | var sendJmsMessage = function(destination, message, type, headers) { | |
| 154 | var message = { | |
| 155 | destination: destination, | |
| 156 | message: message, | |
| 157 | messageType: type | |
| 158 | }; | |
| 159 | // Add message to outbound queue | |
| 160 | if (batchInProgress) { | |
| 161 | messageQueue[messageQueue.length] = {message:message, headers:headers}; | |
| 162 | } else { | |
| 163 | org.activemq.Amq.startBatch(); | |
| 164 | adapter.ajax(uri, { method: 'post', | |
| 165 | data: addClientId( buildParams( [message] ) ), | |
| 166 | error: errorHandler, | |
| 167 | headers: headers, | |
| 168 | success: org.activemq.Amq.endBatch}); | |
| 169 | } | |
| 170 | }; | |
| 171 | ||
| 172 | var buildParams = function(msgs) { | |
| 173 | var s = []; | |
| 174 | for (var i = 0, c = msgs.length; i < c; i++) { | |
| 175 | if (i != 0) s[s.length] = '&'; | |
| 176 | s[s.length] = ((i == 0) ? 'destination' : 'd' + i); | |
| 177 | s[s.length] = '='; | |
| 178 | s[s.length] = msgs[i].destination; | |
| 179 | s[s.length] = ((i == 0) ? '&message' : '&m' + i); | |
| 180 | s[s.length] = '='; | |
| 181 | s[s.length] = msgs[i].message; | |
| 182 | s[s.length] = ((i == 0) ? '&type' : '&t' + i); | |
| 183 | s[s.length] = '='; | |
| 184 | s[s.length] = msgs[i].messageType; | |
| 185 | } | |
| 186 | return s.join(''); | |
| 187 | } | |
| 188 | ||
| 189 | // add clientId to data if it exists, before passing data to ajax connection adapter. | |
| 190 | var addClientId = function( data ) { | |
| 191 | var output = data || ''; | |
| 192 | if( clientId ) { | |
| 193 | if( output.length > 0 ) { | |
| 194 | output += '&'; | |
| 195 | } | |
| 196 | output += 'clientId='+clientId; | |
| 197 | } | |
| 198 | return output; | |
| 199 | } | |
| 200 | ||
| 201 | return { | |
| 202 | // optional clientId can be supplied to allow multiple clients (browser windows) within the same session. | |
| 203 | init : function(options) { | |
| 204 | connectStatusHandler = options.connectStatusHandler || function(connected){}; | |
| 205 | uri = options.uri || '/amq'; | |
| 206 | pollDelay = typeof options.pollDelay == 'number' ? options.pollDelay : 0; | |
| 207 | timeout = typeof options.timeout == 'number' ? options.timeout : 25; | |
| 208 | logging = options.logging; | |
| 209 | clientId = options.clientId; | |
| 210 | adapter.init(options); | |
| 211 | sendPoll(); | |
| 212 | ||
| 213 | }, | |
| 214 | ||
| 215 | startBatch : function() { | |
| 216 | batchInProgress = true; | |
| 217 | }, | |
| 218 | ||
| 219 | endBatch : function() { | |
| 220 | if (messageQueue.length > 0) { | |
| 221 | var messagesToSend = []; | |
| 222 | var messagesToQueue = []; | |
| 223 | var outgoingHeaders = null; | |
| 224 | ||
| 225 | // we need to ensure that messages which set headers are sent by themselves. | |
| 226 | // if 2 'listen' messages were sent together, and a 'selector' header were added to one of them, | |
| 227 | // AMQ would add the selector to both 'listen' commands. | |
| 228 | for(i=0;i<messageQueue.length;i++) { | |
| 229 | // a message with headers should always be sent by itself. if other messages have been added, send this one later. | |
| 230 | if ( messageQueue[ i ].headers && messagesToSend.length == 0 ) { | |
| 231 | messagesToSend[ messagesToSend.length ] = messageQueue[ i ].message; | |
| 232 | outgoingHeaders = messageQueue[ i ].headers; | |
| 233 | } else if ( ! messageQueue[ i ].headers && ! outgoingHeaders ) { | |
| 234 | messagesToSend[ messagesToSend.length ] = messageQueue[ i ].message; | |
| 235 | } else { | |
| 236 | messagesToQueue[ messagesToQueue.length ] = messageQueue[ i ]; | |
| 237 | } | |
| 238 | } | |
| 239 | var body = buildParams(messagesToSend); | |
| 240 | messageQueue = messagesToQueue; | |
| 241 | org.activemq.Amq.startBatch(); | |
| 242 | adapter.ajax(uri, { | |
| 243 | method: 'post', | |
| 244 | headers: outgoingHeaders, | |
| 245 | data: addClientId( body ), | |
| 246 | success: org.activemq.Amq.endBatch, | |
| 247 | error: errorHandler}); | |
| 248 | } else { | |
| 249 | batchInProgress = false; | |
| 250 | } | |
| 251 | }, | |
| 252 | ||
| 253 | // Send a JMS message to a destination (eg topic://MY.TOPIC). Message | |
| 254 | // should be xml or encoded xml content. | |
| 255 | sendMessage : function(destination, message) { | |
| 256 | sendJmsMessage(destination, message, 'send'); | |
| 257 | }, | |
| 258 | ||
| 259 | // Listen on a channel or topic. | |
| 260 | // handler must be a function taking a message argument | |
| 261 | // | |
| 262 | // Supported options: | |
| 263 | // selector: If supplied, it should be a SQL92 string like "property-name='value'" | |
| 264 | // http://activemq.apache.org/selectors.html | |
| 265 | // | |
| 266 | // Example: addListener( 'handler', 'topic://test-topic', function(msg) { return msg; }, { selector: "property-name='property-value'" } ) | |
| 267 | addListener : function(id, destination, handler, options) { | |
| 268 | messageHandlers[id] = handler; | |
| 269 | var headers = options && options.selector ? {selector:options.selector} : null; | |
| 270 | sendJmsMessage(destination, id, 'listen', headers); | |
| 271 | }, | |
| 272 | ||
| 273 | // remove Listener from channel or topic. | |
| 274 | removeListener : function(id, destination) { | |
| 275 | messageHandlers[id] = null; | |
| 276 | sendJmsMessage(destination, id, 'unlisten'); | |
| 277 | }, | |
| 278 | ||
| 279 | // for unit testing | |
| 280 | getMessageQueue: function() { | |
| 281 | return messageQueue; | |
| 282 | }, | |
| 283 | testPollHandler: function( data ) { | |
| 284 | return pollHandler( data ); | |
| 285 | } | |
| 286 | }; | |
| 287 | }(); | |
