websocket的简单应用—实现网页聊天/聊天室(区分用户)
硬件环境:Wind7
开发环境:eclipse+jdk1.7+tomcat9.0+maven
实现了简单的浏览器端根据不同用户发送消息显示在网页上(即简单的聊天室的实现)
下面开始:
1.首先我们都知道websocket是基于tcp的一种新型的网络协议,它实现了双工程通信(允许浏览器发信息给服务器)
2.最大的特点是他是持久化的网络通信协议
至于和http的优缺点我就不说了,那么直接开始撸代码吧
首先是在前端页面(jsp的,html是一样的)
<%@ page language="java" pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<meta>
<title>Java后端WebSocket的Tomcat实现</title>
</head>
<body>
Welcome<br/><input id="text" type="text"/>
<button "send()">发送消息</button>
<hr/>
<button "closeWebSocket()">关闭WebSocket连接</button>
<hr/>
<div id="message"></div>
</body>
<script type="text/javascript" src="js/jquery-3.3.1.js"></script>
<script type="text/javascript">
var websocket = null;
//判断当前浏览器是否支持WebSocket
if ('WebSocket' in window) {
websocket = new WebSocket("ws://localhost:8080/testDemo/websocket/1");
}
else {
alert('当前浏览器 Not support websocket')
}
//连接发生错误的回调方法
websocket.onerror = function () {
setMessageInnerHTML("WebSocket连接发生错误");
};
//连接成功建立的回调方法
websocket.onopen = function () {
console.info("连接打开...")
setMessageInnerHTML("WebSocket连接成功");
}
//接收到消息的回调方法
websocket.onmessage = function (event) {
console.info(event.data);
setMessageInnerHTML(event.data);
}
//连接关闭的回调方法
websocket.onclose = function () {
console.info("连接关闭...")
setMessageInnerHTML("WebSocket连接关闭");
}
//监听窗口关闭事件,当窗口关闭时,主动去关闭websocket连接,防止连接还没断开就关闭窗口,server端会抛异常。
window.onbeforeunload = function () {
closeWebSocket();
}
//将消息显示在网页上
function setMessageInnerHTML(innerHTML) {
var message = document.getElementById("message").innerHTML += innerHTML + '<br/>';
document.getElementById("message").innerHTML=message;
}
//关闭WebSocket连接
function closeWebSocket() {
websocket.close();
}
//发送消息
function send() {
var message = document.getElementById('text').value;
websocket.send('{"id":2,"message":"'+message+'"}');
}
</script>
</html>
那么在后端:
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
@ServerEndpoint("/websocket/{id}")
public class WebsocketController {
//存放客户端对应的mywebsocket对象
// private static CopyOnWriteArraySet<WebsocketController> websocketControllers = new CopyOnWriteArraySet<WebsocketController>();
private static java.util.concurrent.ConcurrentHashMap<String,WebsocketController> websocketControllers = new java.util.concurrent.ConcurrentHashMap<String,WebsocketController>();
private Session session;//会话
private String id; //表示每一个Session
/**
* 建立连接调用方法
*/
@OnOpen
public void onOnpen(Session session,@PathParam("id") String id) {
System.out.println("建立了连接..."+id);
this.session=session;
this.id = id;
// websocketControllers.add(this);//存放到set中
websocketControllers.put(this.id,this);//存放到set中
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose(){
System.out.println("连接关闭...");
// websocketControllers.remove(this); //从set中删除
websocketControllers.remove(this.id); //从set中删除
}
/**
* 收到客户端消息后调用的方法
* @param message 客户端发送过来的消息
* @param session 可选的参数
*/
@OnMessage
public void onMessage(String message, Session session) {
//消息的格式:{"id":2,"message":"+message+"}
//new JsonParser()
//new JSONPObject()
int i1 = message.indexOf(":");
int i2 = message.indexOf(",");
String id=message.substring(i1+1, i2);
int i3 = message.lastIndexOf(":");
//int i4 = message.lastIndexOf(",");
String msg=message.substring(i3);
System.out.println(id+"来自客户端的消息:" + message);
System.out.println(id+"---------");
//取得对应的id
WebsocketController item = websocketControllers.get(id);
try {
item.sendMessage(msg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//群发消息
/*for(WebsocketController item: websocketControllers){
try {
item.sendMessage(message);
// this.session.getAsyncRemote().sendText(message);
} catch (IOException e) {
e.printStackTrace();
continue;
}
}*/
}
/**
* 发生错误时调用
* @param session
* @param error
*/
@OnError
public void onError(Session session, Throwable error){
System.out.println("发生错误..");
error.printStackTrace();
}
/**
* @param message
* @throws IOException
*/
public void sendMessage(String message) throws IOException{
System.out.println("开始发送消息");
//this.session.getBasicRemote().sendText(message);
this.session.getAsyncRemote().sendText(message);
}
}
pom.xml文件内容(非maven构建项目引入相关Jar文件即可)
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.accp.springmvc</groupId>
<artifactId>websocket</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>websocket Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!--1.志相关依赖 -->
<!--slf4j规范接口 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.12</version>
</dependency>
<!--logback日志 -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.1.7</version>
</dependency>
<!--实现slf4j接口并整合 -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.7</version>
</dependency>
<!-- jackson json配置 -->
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context-support -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.0.0.RELEASE</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-expression -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>5.1.2.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>5.0.0.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.jsqlparser/jsqlparser -->
<dependency>
<groupId>com.github.jsqlparser</groupId>
<artifactId>jsqlparser</artifactId>
<version>1.3</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.12</version>
</dependency>
<!-- 导入分页插件 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.0.0</version>
</dependency>
<!--Servlet web相关依赖 -->
<!--jsp相关依赖 -->
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>8.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>websocket</finalName>
</build>
</project>
web.xml的内容
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
id="WebApp_ID" version="3.1">
<display-name>jsp-0402</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 核心控制器:与Struts的核心过滤器一样 -->
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- tomcat启动时,运行该Servlet -->
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 处理中文乱码的过滤器 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
如果你看着代码脑袋疼,那你可以点击github网址,里面有现成的呦!
那简单的websocket应用就是这样了,撸起来!