利刃出鞘_Tomcat 核心原理解析（十一）-- Tomcat 附加功能 WebSocket -- 2
一、Tomcat专题 - WebSocket - 案例 - 登录功能
1、在项目 dzs168_chat_room 中，导入 tomcat 项目依赖（ dzs168_chat_room/web/lib/ ）
bash
idea ---> File
---> Project Structure
---> Modules
选择我们的项目 dzs168_chat_room
---> Dependencies: 点击 + 添加
---> Library...
---> Application Server Libraries
---> Tcomcat
---> Add Selected
---> Apply
---> OK。2、项目 dzs168_chat_room 中，login.jsp 页面。
java
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html lang="en">
<head>
<title>段子手聊天室------登录</title>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta name="keywords"
content="Transparent Sign In Form Responsive Widget,Login form widgets, Sign up Web forms , Login signup Responsive web form,Flat Pricing table,Flat Drop downs,Registration Forms,News letter Forms,Elements"/>
<script type="application/x-javascript">
addEventListener("load", function () {
setTimeout(hideURLbar, 0);
}, false);
function hideURLbar() {
window.scrollTo(0, 1);
}
</script>
<script src="js/jquery-1.9.1.min.js"></script>
<link rel="icon" href="img/chat.ico" type="image/x-icon"/>
<link rel="stylesheet" href="css/font-awesome.css"/> <!-- Font-Awesome-Icons-CSS -->
<link rel="stylesheet" href="css/login.css" type="text/css" media="all"/> <!-- Style-CSS -->
</head>
<body class="background">
<div class="header-w3l">
<h1>段子手168聊天室</h1>
</div>
<div class="main-content-agile">
<div class="sub-main-w3">
<h2>登录</h2>
<form>
<div class="icon1">
<input placeholder="用户名" id="username" type="text"/>
</div>
<div class="icon2">
<input placeholder="密码" id="password" type="password"/>
</div>
<div class="clear"></div>
<input type="button" value="登录" onclick="login()"/>
</form>
</div>
</div>
<div class="footer">
<p>段子手168 版权所有Copyright 2024-9-1 All Rights Reserved </p>
</div>
</body>
<script type="text/javascript">
function login() {
$.ajax({
type: 'POST',
url: '/login',
dataType: 'json',
data: {
username: $("#username").val(),
password: $("#password").val()
},
success: function (data) {
if (data.success) {
window.location.href = "chat.jsp";
} else {
alert(data.message);
}
}
});
}
</script>
</html>
<!-- project_tomcat\dzs168_chat_room\web\login.jsp -->3、项目 dzs168_chat_room 中，chat.jsp 页面。
java
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="format-detection" content="telephone=no">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=0, minimum-scale=1.0, maximum-scale=1.0">
<meta name="mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta content="yes" name="apple-mobile-web-app-capable">
<meta content="yes" name="apple-touch-fullscreen">
<meta name="full-screen" content="yes">
<meta content="default" name="apple-mobile-web-app-status-bar-style">
<meta name="screen-orientation" content="portrait">
<meta name="browsermode" content="application">
<meta name="msapplication-tap-highlight" content="no">
<meta name="x5-orientation" content="portrait">
<meta name="x5-fullscreen" content="true">
<meta name="x5-page-mode" content="app">
<base target="_blank">
<title>段子手168-聊天室</title>
<link href="css/bootstrap.min.css" rel="stylesheet" type="text/css"/>
<link rel="stylesheet" href="css/chat.css">
<script src="js/jquery-1.9.1.min.js"></script>
<script type="text/javascript">
<%
String name = session.getAttribute("username")+"";
%>
var self = "<%= name %>";
</script>
<script type="text/javascript" src="js/ws.js"></script>
</head>
<body onload="startWebSocket(self);">
<img style="width:100%;height:100%" src="img/chat_bg.jpg">
<div class="abs cover contaniner">
<div class="abs cover pnl">
<div class="top pnl-head" style="padding: 20px ; color: white;" id="userName"></div>
<div class="abs cover pnl-body" id="pnlBody">
<div class="abs cover pnl-left">
<div class="abs cover pnl-msgs scroll" id="show">
<div class="pnl-list" id="hists"><!-- 历史消息 --></div>
<div class="pnl-list" id="msgs">
<!-- 消息这展示区域 -->
</div>
</div>
<div class="abs bottom pnl-text">
<div class="abs cover pnl-input">
<textarea class="scroll" id="context_text" onkeydown="sendMessage(self)" wrap="hard" placeholder="在此输入文字信息..."></textarea>
<div class="abs atcom-pnl scroll hide" id="atcomPnl">
<ul class="atcom" id="atcom"></ul>
</div>
</div>
<div class="abs br pnl-btn" id="submit" style="background-color: rgb(32, 196, 202); color: rgb(255, 255, 255);" onclick="sendMsg(self)">
发送
</div>
<div class="pnl-support" id="copyright"><a href="http://www.itcast.cn">段子手168,版本所有</a></div>
</div>
</div>
<div class="abs right pnl-right">
<div class="slider-container hide"></div>
<div class="pnl-right-content">
<div class="pnl-tabs">
<div class="tab-btn active" id="hot-tab">好友列表</div>
</div>
<div class="pnl-hot">
<ul class="rel-list unselect" id="userlist">
</ul>
</div>
</div>
<div class="pnl-right-content">
<div class="pnl-tabs">
<div class="tab-btn active">系统广播</div>
</div>
<div class="pnl-hot">
<ul class="rel-list unselect" id="broadcastList">
</ul>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
<!-- project_tomcat\dzs168_chat_room\web\chat.jsp -->4、在项目 dzs168_chat_room 中，创建 用户登录的 servlet 类 LoginServlet.java
bash
/**
* project_tomcat\dzs168_chat_room\src\djh\it\servlet\LoginServlet.java
*
* 2024-9-1 创建 用户登录的 servlet 类 LoginServlet.java
*/
package djh.it.servlet;
import com.alibaba.fastjson.JSON;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
@WebServlet(name = "loginServlet",urlPatterns = "/login")
public class LoginServlet extends HttpServlet {
private static final String PASSWORD = "dzs168";
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//处理中文乱码问题
resp.setCharacterEncoding("UTF-8");
//1. 接收页面传递的参数 , 用户名/密码
String username = req.getParameter("username");
String password = req.getParameter("password");
Map resultMap = new HashMap();
//2. 判定用户名密码是否正确
//3. 如果正确, 响应登录成功的信息
if(PASSWORD.equals(password)){
resultMap.put("success",true);
resultMap.put("message","登录成功");
req.getSession().setAttribute("username",username);
}else{//4. 如果不正确, 响应登录失败的信息
resultMap.put("success",false);
resultMap.put("message","用户名或密码错误");
}
//5. 响应数据
resp.getWriter().write(JSON.toJSONString(resultMap));
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req,resp);
}
}5、运行 tomcat 服务，进行测试。浏览器地址栏输入：localhost:8080/ 输入错误密码 和 正确密码，分别进行测试。
二、Tomcat专题 - WebSocket - 案例 - OnOpen
1、在项目 dzs168_chat_room 中，工具类 MessageUtil.java
bash
/**
* project_tomcat.dzs168_chat_room.src.djh.it.utils.MessageUtil.java
*
* 2024-9-2 工具类 MessageUtil.java
*/
package djh.it.utils;
import com.alibaba.fastjson.JSON;
import java.util.HashMap;
import java.util.Map;
public class MessageUtil {
public final static String TYPE = "type";
public final static String DATA = "data";
public final static String FROM_NAME = "fromName";
public final static String TO_NAME = "toName";
public final static String TYPE_MESSAGE = "message";
public final static String TYPE_USER = "user";
//组装消息, 然后返回一个json格式的消息数据
public static String getContent(String type, String fromName, String toName, String content) {
Map<String, Object> userMap = new HashMap<String, Object>();
userMap.put(MessageUtil.TYPE, type);
userMap.put(MessageUtil.DATA, content);
userMap.put(MessageUtil.FROM_NAME, fromName);
userMap.put(MessageUtil.TO_NAME, toName);
String jsonMsg = JSON.toJSONString(userMap);
return jsonMsg;
}
}2、在项目 dzs168_chat_room 中，创建 获取 HttpSession 的 GetHttpSessionConfigurator.java 类，
bash
/**
* project_tomcat\dzs168_chat_room\src\djh\it\websocket\GetHttpSessionConfigurator.java
*
* 2024-9-2 创建 获取 HttpSession 的 GetHttpSessionConfigurator.java 类，
*/
package djh.it.websocket;
import javax.servlet.http.HttpSession;
import javax.websocket.HandshakeResponse;
import javax.websocket.server.HandshakeRequest;
import javax.websocket.server.ServerEndpointConfig;
public class GetHttpSessionConfigurator extends ServerEndpointConfig.Configurator {
@Override //重写方法
public void modifyHandshake(ServerEndpointConfig config, HandshakeRequest request, HandshakeResponse response) {
HttpSession httpSession = (HttpSession) request.getHttpSession();
config.getUserProperties().put(HttpSession.class.getName(),httpSession);
}
}3、在项目 dzs168_chat_room 中，创建 websocket 类 ChatSocket.java
bash
/**
* project_tomcat\dzs168_chat_room\src\djh\it\websocket\ChatSocket.java
*
* 2024-9-2 创建 websocket 类 ChatSocket.java
*/
package djh.it.websocket;
import djh.it.utils.MessageUtil;
import javax.servlet.http.HttpSession;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.util.HashMap;
import java.util.Map;
@ServerEndpoint(value = "/websocket",configurator = GetHttpSessionConfigurator.class )
public class ChatSocket {
private Session session;
private HttpSession httpSession;
//保存当前系统中登录的用户的HttpSession信息, 及对应的Endpoint实例信息
private static Map<HttpSession , ChatSocket> onlineUsers = new HashMap<HttpSession, ChatSocket>();
private static int onlineCount = 0;
@OnOpen
public void onOpen(Session session, EndpointConfig config){
//1. 记录webSocket的会话信息对象Session
this.session = session;
//2. 获取当前登录用户HttpSession信息.
HttpSession httpSession = (HttpSession) config.getUserProperties().get(HttpSession.class.getName());
this.httpSession = httpSession;
System.out.println("当前登录用户 : " + httpSession.getAttribute("username") +", Endpoint : " +hashCode());
//3. 记录当前登录用户信息, 及对应的Endpoint实例
if (httpSession.getAttribute("username") != null){
onlineUsers.put(httpSession,this);
}
//4. 获取当前所有登录用户 --------> DZS168,dzs,TOM...
String names = getNames();
//5. 组装消息 ---> {"data":"dzs168,Deng,study","toName":"","fromName":"","type":"user"}
String message = MessageUtil.getContent(MessageUtil.TYPE_USER, "", "", names);
//6. 通过广播的形式发送消息
//session.getBasicRemote().sendText("");
broadcastAllUsers(message);
//7. 记录当前用户登录数 .
incrCount();
}
// 发送广播消息
private void broadcastAllUsers(String message) {
for (HttpSession hsession : onlineUsers.keySet()) {
try {
onlineUsers.get(hsession).session.getBasicRemote().sendText(message);
} catch (Exception e) {
e.printStackTrace();
}
}
}
//获取所有的在线用户
private String getNames() {
String names = "";
if(onlineUsers.size()>0){
for (HttpSession hsession : onlineUsers.keySet()) {
String username = (String) hsession.getAttribute("username");
names += username+",";
}
}
return names.substring(0,names.length()-1);
}
public int getOnlineCount(){
return onlineCount;
}
public synchronized void incrCount(){
onlineCount ++;
}
public synchronized void decrCount(){
onlineCount --;
}
}三、Tomcat专题 - WebSocket - 案例 - OnOpen测试
1、运行 tomcat 服务，进行测试。观察控制台输出结果。
2、多个 浏览器地址栏输入：localhost:8080/ 进行测试，观察控制台输出结果。
上一节关联链接请点击
# 利刃出鞘_Tomcat 核心原理解析（十一）-- WebSocket -- 1
利刃出鞘_Tomcat 核心原理解析（十）-- Tomcat 性能调优--2