springboot搭建WebSocket服务端_springboot websocket 搭建

作者：喵喵爱编程 | 2024-07-28 03:02:49

踩

springboot websocket 搭建

基于springboot框架编写一个WebSocket服务端，并通过简单的html界面模拟客户端验证服务端连接。

1、pom.xml


<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
 
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
 
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
 
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
 
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
 
    <dependencies>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

2、application.yml


spring:
  thymeleaf:
    prefix: classpath:/templates/

3、Server端代码

3.1、ServerEndpointExporter

首先要注入ServerEndpointExporter，这个bean会自动注册使用了@ServerEndpoint注解声明的Websocket endpoint。要注意，如果使用独立的servlet容器，而不是直接使用springboot的内置容器，就不要注入ServerEndpointExporter，因为它将由容器自己提供和管理。


package com.example.demo.config;
 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
 
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
 
}

3.2 WebSocketServer


package com.example.demo.webSocket;
 
 
import org.springframework.stereotype.Component;
 
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
 
@ServerEndpoint("/webSocketServer")
@Component
public class WebSocketDemo {
 
 
    @OnOpen
    public void onOpen(Session session) {
        System.out.println("新开启了一个webSocket连接" + session.getId());
    }
 
    @OnMessage
    public String onMessage(String message, Session session) {
        System.out.println("收到客户端发送的信息:"+message);
        System.out.println("当前的sessionId:"+session.getId());
        return "SUCCESS";
    }
 
    @OnClose
    public void onClose(Session session, CloseReason reason) {
        System.out.println("webSocket连接关闭：sessionId:"+session.getId() + "关闭原因是："+reason.getReasonPhrase() + "code:"+reason.getCloseCode());
    }
 
 
    @OnError
    public void onError(Throwable t) {
        t.printStackTrace();
    }
 
}

4、前端html界面


<!DOCTYPE html>
<html>
 
<head>
    <meta name="viewport" content="width=device-width" />
    <title>WebSocket 客户端</title>
</head>
 
<body>
<div>
    <input type="button" id="btnConnection" value="连接" />
    <input type="button" id="btnClose" value="关闭" />
    <input type="button" id="btnSend" value="发送" />
</div>
<script src="/jquery-3.3.1.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
    $(function(){
        var socket;
        if(typeof(WebSocket) == "undefined") {
            alert("您的浏览器不支持WebSocket");
            return;
        }
        $("#btnConnection").click(function() {
            //实现化WebSocket对象，指定要连接的服务器地址与端口
            socket = new WebSocket("ws://localhost:8080/webSocketServer");
            //打开事件
            socket.onopen = function() {
                alert("Socket 已打开");
                //socket.send("这是来自客户端的消息" + location.href + new Date());
            };
            //获得消息事件
            socket.onmessage = function(msg) {
                alert(msg.data);
            };
            //关闭事件
            socket.onclose = function() {
                alert("Socket已关闭");
            };
            //发生了错误事件
            socket.onerror = function() {
                alert("发生了错误");
            }
        });
 
        //发送消息
        $("#btnSend").click(function() {
            socket.send("这是来自客户端的消息" + location.href + new Date());
        });
 
        //关闭
        $("#btnClose").click(function() {
            socket.close();
        });
    });
</script>
</body>
 
</html>

5、跳转界面代码


package com.example.demo.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
 
@Controller
public class HelloWorldController {
    @GetMapping("/hello")
    public String hello() {
        return "/webSocketDemo";
    }
}

6、目录结构

7、当需要在websocket服务端注入Service或者Dao进行其他的业务逻辑时，常规注入是会产生空指针异常的。

我们需要在websocket中注入applilcationContext对象，从上下文对象中获取。

方法如下：

7.1 先在main方法启动时将application对象注入到webSocket对象中


public static void main(String[] args) {
    ConfigurableApplicationContext applicationContext = SpringApplication.run(RangerSocketApplication.class, args);
    GatewayWebSocket.setApplicationContext(applicationContext);
}

7.2 在webSocket服务端设置注入方法，并基于上下文进行获取


private static ApplicationContext applicationContext;
 
public static void setApplicationContext(ApplicationContext context) {
    applicationContext = context;
}

7.3 在获取时赋值


private GatewayDao gatewayDao;
 
if(gatewayDao == null) {
    gatewayDao = applicationContext.getBean(GatewayDao.class);
}

声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/w/喵喵爱编程/article/detail/892573