使用websocket技术实现消息推送到网页效果。
主要说两种，一种是servlet，一种是struts2. 两种方法后台稍微有点区别，交叉没有试过。
初步测试已调通此两种方法。
第一种：
servlet
import java.io.IOException;import java.nio.ByteBuffer;import java.nio.CharBuffer;import java.util.ArrayList;import javax.servlet.http.HttpServletRequest;import javax.websocket.server.ServerEndpoint;import org.apache.catalina.websocket.MessageInbound;import org.apache.catalina.websocket.StreamInbound;import org.apache.catalina.websocket.WebSocketServlet;import org.apache.catalina.websocket.WsOutbound;public class WebServelt extends WebSocketServlet {private static final long serialVersionUID = -4853540828121130946L;private static ArrayList<MyMessageInbound> mmiList = new ArrayList<MyMessageInbound>();@Overrideprotected StreamInbound createWebSocketInbound(String str,HttpServletRequest request) {return new MyMessageInbound();}private class MyMessageInbound extends MessageInbound {WsOutbound myoutbound;@Overridepublic void onOpen(WsOutbound outbound) {try {System.out.println("Open Client.");this.myoutbound = outbound;mmiList.add(this);outbound.writeTextMessage(CharBuffer.wrap("Hello!"));} catch (IOException e) {e.printStackTrace();}}@Overridepublic void onClose(int status) {System.out.println("Close Client.");mmiList.remove(this);}//当服务器端收到信息的时候,就对所有的连接进行遍历并且把收到的信息发送给所有用户@Overridepublic void onTextMessage(CharBuffer cb) throws IOException {System.out.println("Accept Message : " + cb);for (MyMessageInbound mmib : mmiList) {CharBuffer buffer = CharBuffer.wrap(cb);mmib.myoutbound.writeTextMessage(buffer);mmib.myoutbound.flush();}}@Overridepublic void onBinaryMessage(ByteBuffer bb) throws IOException {}} }
页面
<!DOCTYPE html><html><head><meta charset=UTF-8><title>Tomcat WebSocket Chat</title><script> //建立客户端websocketvar ws = new WebSocket("ws://localhost:8080/Backstage/ws/wsServlet");//定义ws的一些回调函数 ws.onopen = function() { };//当有消息传过来时执行的操作ws.onmessage = function(message) {document.getElementById("chatlog").textContent += message.data + "\n";};function postToServer() {ws.send(document.getElementById("msg").value);document.getElementById("msg").value = "";}function closeConnect() {ws.close();}</script></head><body><textarea id="chatlog" readonly></textarea><br /><input id="msg" type="text" /><button type="submit" id="sendButton" onClick="postToServer()">Send!</button><button type="submit" id="sendButton" onClick="closeConnect()">End</button></body></html>web.xml
<display-name>Websocket</display-name><servlet><servlet-name>wsServlet</servlet-name><servlet-class>com.backstage.calendar.WebServelt</servlet-class></servlet><servlet-mapping><servlet-name>wsServlet</servlet-name><url-pattern>/ws/wsServlet</url-pattern></servlet-mapping>
效果：
第二种
@ServerEndpoint("/ws/websocket")public class WebSocketTest {@OnMessagepublic void onMessage(String message,Session session)throws IOException, InterruptedException{System.out.println("***************");session.getBasicRemote().sendText(" this is message");int sentMessage = 0;while(sentMessage < 3){Thread.sleep(5000);session.getBasicRemote().sendText(" this is one mess " + sentMessage);sentMessage++;}session.getBasicRemote().sendText(" message send over ");}@OnOpenpublic void onOpen(){System.out.println(" client connected ");}@OnClosepublic void onClose(){System.out.println(" connection closed ");}}
使用@ServerEndpoint("/ws/websocket") 进行访问
html
<!DOCTYPE html><html><head><title>Testing websockets</title></head><body> <div><input type="submit" value="Start" onclick="start()" /> </div> <div id="messages"></div> <script type="text/javascript">var webSocket;if ('WebSocket' in window) {webSocket = new WebSocket("ws://localhost:8080/Backstage/ws/websocket");} else if ('MozWebSocket' in window) {webSocket = new MozWebSocket("ws://localhost:8080/websocket");} else {alert("js");webSocket = new SockJS(":8080/Origami/sockjs/webSocketServer");}webSocket.onerror = function(event) {onError(event)};webSocket.onopen = function(event) {onOpen(event)};webSocket.onmessage = function(event) {onMessage(event)};function onMessage(event) {document.getElementById('messages').innerHTML+= '<br />' + event.data;}function onOpen(event) {document.getElementById('messages').innerHTML= 'Connection established';}function onError(event) {//console.log(event);//console.log(event.data);alert(event.data);}function start() {webSocket.send('hello');return false;} </script></body></html>效果
失败是什么?没有什么.只是更走近成功一步,
