WebSocket.之.基础入门-断开连接处理

ebSocket.之.基础入门-断开连接处理

在《WebSocket.之.基础入门-后端响应消息》的代码基础之上，继续更新代码。代码只改动了：TestSocket.java 和 index.jsp 两个文件。

先说问题：

　　当前后端建立连接之后，如果此时关闭浏览器，或者点击浏览器的回退。只要退出了建立连接的页面。后台程序是会报错的。分别如下图所示：

　　正常建立连接页面：

　　

　　

　　

　　

　　现在退出当前建立连接的页面，后台日志如下所示：

当前session的id是：0
从前端页面传过来的数据是：早上好..
 3 十月 14, 2018 8:52:41 上午 org.apache.tomcat.websocket.pojo.PojoEndpointBase onError
 4 严重: No error handling configured for [com.charles.socket.TestSocket] and the following error occurred
 5 java.io.IOException: java.util.concurrent.ExecutionException: java.net.SocketException: Software caused connection abort: socket write error
 6     at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:286)
 7     at org.apache.tomcat.websocket.WsSession.sendCloseMessage(WsSession.java:572)
 8     at org.apache.tomcat.websocket.WsSession.onClose(WsSession.java:495)
 9     at org.apache.tomcat.websocket.WsFrameBase.processDataControl(WsFrameBase.java:348)
10     at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:290)
11     at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:131)
12     at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:67)
13     at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:204)
14     at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:203)
15     at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:93)
16     at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:635)
17     at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
18     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
19     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
20     at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
21     at java.lang.Thread.run(Thread.java:748)
22 Caused by: java.util.concurrent.ExecutionException: java.net.SocketException: Software caused connection abort: socket write error
23     at org.apache.tomcat.websocket.FutureToSendHandler.get(FutureToSendHandler.java:120)
24     at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:281)
25     ... 15 more
26 Caused by: java.net.SocketException: Software caused connection abort: socket write error
27     at java.net.SocketOutputStream.socketWrite0(Native Method)
28     at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
29     at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
30     at org.apache.coyote.http11.upgrade.BioServletOutputStream.doWrite(BioServletOutputStream.java:38)
31     at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.writeInternal(AbstractServletOutputStream.java:153)
32     at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.write(AbstractServletOutputStream.java:121)
33     at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.onWritePossible(WsRemoteEndpointImplServer.java:94)
34     at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.doWrite(WsRemoteEndpointImplServer.java:81)
35     at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.writeMessagePart(WsRemoteEndpointImplBase.java:456)
36     at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessage(WsRemoteEndpointImplBase.java:344)
37     at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:276)
38     ... 15 more

　　

　　现在开始处理上面的异常

TestSocket.java

package com.charles.socket;

import java.io.IOException;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint(value = "/helloSocket")
public class TestSocket {

    /***
     * 当建立链接时，调用的方法.
     * @param session
     */
    @OnOpen
    public void open(Session session) {
        
        System.out.println("开始建立了链接...");
        System.out.println("当前session的id是：" + session.getId());
    }
    
    /***
     * 处理消息的方法.
     * @param session
     */
    @OnMessage
    public void message(Session session, String data) {
        
        System.out.println("开始处理消息...");
        System.out.println("当前session的id是：" + session.getId());
        System.out.println("从前端页面传过来的数据是：" + data);
        
        
        String message = "你好，我是后端程序...";
        try {
            session.getBasicRemote().sendText(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
    /***
     * 处理断开连接的方法.
     * @param session
     */
    @OnClose
    public void close(Session session) {
        System.out.println("Session-ID是："+session.getId() + ",退出了系统...欢迎下次再来...");
    }
    
}

index.jsp 代码

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Charles-WebSocket</title>

<script type="text/javascript">
    
    var websocket = null;
    var target = "ws://localhost:8080/websocket/helloSocket";
    
    function buildConnection() {
        
        if('WebSocket' in window) {
            websocket = new WebSocket(target);        
        } else if('MozWebSocket' in window) {
            websocket = MozWebSocket(target);
        } else {
            window.alert("浏览器不支持WebSocket");
        }
        
        // 添加监听消息的方法
        websocket.onmessage = function(event) {
             console.log(event)
             console.log(event.data)
             document.getElementById("serverMsg").innerHTML = "<p>后端消息 ："+ event.data +"</p>"
        }
        
        // 监听断开连接的方法.
        websocket.onclose = function(event) {
            // 如没有业务需求，可以不写这个关闭监听的方法.
            // 业务需求，例如：聊天室，当某人退出的时候，会给出提示，xxx退出了...
        }
    }
    
    // 退出系统时, 关闭建立的WebSocket链接
    window.onbeforeunload = function () {
        websocket.close();
    }
    
    
    // 往后台服务器发送消息.
    function sendMessage() {
        
        var sendmsg = document.getElementById("sendMsg").value;
        console.log("发送的消息：" + sendmsg);
        
        // 发送至后台服务器中.
        websocket.send(sendmsg);
    }
    
</script>
</head>
<body>
    
    <button onclick="buildConnection();">开始建立链接</button>
    <hr>
    <input id="sendMsg" /> <button onclick="sendMessage();">消息发送</button>
    <div id="serverMsg"></div>

</body>
</html>

访问浏览器，输入地址：http://localhost:8080/websocket

建立连接，发送消息，然后在退出，在发送消息，在退出

在次访问系统..并退出...

系统正常运行，异常信息（... Caused by: java.net.SocketException: Software caused connection abort: socket write error.. ）解决.

如有问题，欢迎纠正！！！

如有转载，请标明源处：https://www.cnblogs.com/Charles-Yuan/p/9785147.html