WebSocket +Jetty+jQuery 实现服务器消息推送例子
package flowersinthesand.example;import java.io.IOException;import java.io.PrintWriter;import java.util.LinkedHashMap;import java.util.Map;import java.util.Queue;import java.util.UUID;import java.util.concurrent.BlockingQueue;import java.util.concurrent.ConcurrentHashMap;import java.util.concurrent.ConcurrentLinkedQueue;import java.util.concurrent.LinkedBlockingQueue;import javax.servlet.AsyncContext;import javax.servlet.AsyncEvent;import javax.servlet.AsyncListener;import javax.servlet.ServletConfig;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.eclipse.jetty.util.UrlEncoded;import org.eclipse.jetty.websocket.WebSocket;import org.eclipse.jetty.websocket.WebSocketServlet;import com.google.gson.Gson;@WebServlet(urlPatterns = "/chat", asyncSupported = true)public class ChatServlet extends WebSocketServlet {private static final long serialVersionUID = 4805728426990609124L;private Map<String, AsyncContext> asyncContexts = new ConcurrentHashMap<String, AsyncContext>();private Queue<ChatWebSocket> webSockets = new ConcurrentLinkedQueue<ChatWebSocket>();private BlockingQueue<String> messages = new LinkedBlockingQueue<String>();private Thread notifier = new Thread(new Runnable() {public void run() {while (true) {try {// Waits until a message arrivesString message = messages.take();// Sends the message to all the AsyncContext's responsefor (AsyncContext asyncContext : asyncContexts.values()) {try {sendMessage(asyncContext.getResponse().getWriter(), message);} catch (Exception e) {asyncContexts.values().remove(asyncContext);}}// Sends the message to all the WebSocket's connectionfor (ChatWebSocket webSocket : webSockets) {try {webSocket.connection.sendMessage(message);} catch (Exception e) {webSockets.remove(webSocket);}}} catch (InterruptedException e) {break;}}}});private void sendMessage(PrintWriter writer, String message) throws IOException {// default message format is message-size ; message-data ;writer.print(message.length());writer.print(";");writer.print(message);writer.print(";");writer.flush();}@Overridepublic void init(ServletConfig config) throws ServletException {super.init(config);notifier.start();}// GET method is used to establish a stream connection@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// Content-Type headerresponse.setContentType("text/plain");response.setCharacterEncoding("utf-8");// Access-Control-Allow-Origin headerresponse.setHeader("Access-Control-Allow-Origin", "*");PrintWriter writer = response.getWriter();// Idfinal String id = UUID.randomUUID().toString();writer.print(id);writer.print(';');// Paddingfor (int i = 0; i < 1024; i++) {writer.print(' ');}writer.print(';');writer.flush();final AsyncContext ac = request.startAsync();ac.addListener(new AsyncListener() {public void onComplete(AsyncEvent event) throws IOException {asyncContexts.remove(id);}public void onTimeout(AsyncEvent event) throws IOException {asyncContexts.remove(id);}public void onError(AsyncEvent event) throws IOException {asyncContexts.remove(id);}public void onStartAsync(AsyncEvent event) throws IOException {}});asyncContexts.put(id, ac);}// POST method is used to communicate with the server@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8");AsyncContext ac = asyncContexts.get(request.getParameter("metadata.id"));if (ac == null) {return;}// close-requestif ("close".equals(request.getParameter("metadata.type"))) {ac.complete();return;}// send-requestMap<String, String> data = new LinkedHashMap<String, String>();data.put("username", request.getParameter("username"));data.put("message", request.getParameter("message"));try {messages.put(new Gson().toJson(data));} catch (InterruptedException e) {throw new IOException(e);}}@Overridepublic WebSocket doWebSocketConnect(HttpServletRequest request, String protocol) {return new ChatWebSocket();}class ChatWebSocket implements WebSocket.OnTextMessage {Connection connection;@Overridepublic void onOpen(Connection connection) {this.connection = connection;webSockets.add(this);}@Overridepublic void onClose(int closeCode, String message) {webSockets.remove(this);}@Overridepublic void onMessage(String queryString) {// Parses query stringUrlEncoded parameters = new UrlEncoded(queryString);Map<String, String> data = new LinkedHashMap<String, String>();data.put("username", parameters.getString("username"));data.put("message", parameters.getString("message"));try {messages.put(new Gson().toJson(data));} catch (InterruptedException e) {throw new RuntimeException(e);}}}@Overridepublic void destroy() {messages.clear();webSockets.clear();asyncContexts.clear();notifier.interrupt();}}

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html代码

<!DOCTYPE html><html><head><title>Chat - Jetty 8</title><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><script type="text/javascript" src="jquery-1.5.0.js"></script><script type="text/javascript" src="jquery.stream-1.2.js"></script><script type="text/javascript">$.stream.setup({enableXDR: true});var chat = {lastUsername: "Donghwan Kim",username: $.trim(window.prompt("Username?")) || "Anonymous" + $(window).width()};$(function() {$.stream("chat", {dataType: "json",context: $("#content")[0],open: function(event, stream) {$("#editor .message").removeAttr("disabled").focus();stream.send({username: chat.username, message: "Hello"});},message: function(event) {if (chat.lastUsername !== event.data.username) {$("<p />").addClass("user").text(chat.lastUsername = event.data.username).appendTo(this);}$("<p />").addClass("message").text(event.data.message).appendTo(this);this.scrollTop = this.scrollHeight;},error: function() {$("#editor .message").attr("disabled", "disabled");},close: function() {$("#editor .message").attr("disabled", "disabled");}});$("#editor .user").text(chat.username);$("#editor .message").keyup(function(event) {if (event.which === 13 && $.trim(this.value)) {$.stream().send({username: chat.username, message: this.value});this.value = "";}});$(window).resize(function() {var content = $("#content").height($(window).height() - $("#editor").outerHeight(true) - 15)[0];content.scrollTop = content.scrollHeight;}).resize();});</script><style>body {padding: 0; margin: 0; min-width: 320px; font-family: 'Trebuchet MS','Malgun Gothic',Verdana,Helvetica,Arial,sans-serif; font-size: 62.5%; color: #333333}.content {height: 100%; overflow-y: auto; padding: 14px 15px 0 25px;}.content p {margin: 0; padding: 0;}.content .user {font-size: 1.8em; color: #3e3e3e; font-weight: bold; letter-spacing: -1px; margin-top: 0.5em;}.content .message {font-size: 1.3em; color: #444444; line-height: 1.7em; word-wrap: break-word;}.editor {margin: 0 25px 15px 25px;}.editor .user {font-size: 1.5em; display: inline-block; margin: 1em;}.editor input {font-family: 'Trebuchet MS','Malgun Gothic',Verdana,Helvetica,Arial,sans-serif;}.editor .message {width: 100%; height: 28px; line-height: 28px; border: medium none; border-color: #E5E5E5 #DBDBDB #D2D2D2; border-style: solid; border-width: 1px;}</style></head><body><div id="content" onsubmit="return false;"><input type="text" disabled="disabled" /></form></div></body></html>

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另需要

jquery-1.5.0.js

jquery.stream-1.2.js

参考?https://code.google.com/p/jquery-stream/

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压力测试插件

https://github.com/kawasima/jmeter-websocket