一、后端springboot代码

1、 引入依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

2 、websocket配置

@Slf4j
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        // 客户端订阅消息的前缀：topic用来广播，user用来实现点对点
        registry.enableSimpleBroker("/topic", "/user");
        // 点对点发送前缀
        registry.setUserDestinationPrefix("/user");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        // 注册STOMP的endpoint，前端建立socket连接时url(http://127.0.0.1:8080/api)
        registry.addEndpoint("/api").setAllowedOrigins("*").withSockJS();
    }
}

3、发送消息(http方式发送消息)

@RestController
@RequestMapping("/socket")
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class WebsocketController {
    private final SimpMessagingTemplate simpMessagingTemplate;

    @PostMapping("/sendMsg")
    public Result<String> sendMsg(){
        simpMessagingTemplate.convertAndSend("/topic/all","今天10点开项目启动会-所有人");
        return Result.SUCCESS();
    }
    @PostMapping("/sendOne")
    public Result<String> sendOne(){
        simpMessagingTemplate.convertAndSendToUser("111111","/queue/cmdFinish","今天10点开项目启动会-linxin");
        return Result.SUCCESS();
    }
}

二、 前端vue代码

1、安装npm依赖包

npm install sockjs-client --save
npm install stompjs --save

2、订阅后端推送的消息（发送消息暂时就用http方式调用后端接口）

<script>
import SockJS from 'sockjs-client/dist/sockjs.min.js';
import Stomp from 'stompjs';
export default {
    data: function() {
        return{
             stompClient:null,
             sockjs:null
        }        
    },
    mounted(){
        this.initWebSocket();
    },
    beforeDestroy() {
        // 页面离开时断开连接
        this.disconnect()
    },
    methods:{
        initWebSocket:function(){
            let that = this;
            // 建立连接对象
            that.socket =  new SockJS("http://127.0.0.1L8080/api");
            // 获取STOMP子协议的客户端对象
            that.stompClient = Stomp.over(that.socket);
            that.stompClient.debug = false
            that.stompClient.reconnect_delay = 5000
            // 建立连接
            that.stompClient.connect({},(frame)=>{
                // 订阅主题
                that.stompClient.subscribe('/topic/all',res=>{
                    console.info('res',res);
                    that.$message({
                        message:res.body,
                        type:'success',
                        duration:3000
                    });
                });
                // 订阅点对点消息 username=111111(对应后端代码 simpMessagingTemplate.convertAndSendToUser("111111","/queue/cmdFinish","今天10点开项目启动会-linxin");)
                that.stompClient.subscribe(`/user/${that.username}/queue/cmdFinish`,res=>{
                    console.info('res',res);
                    that.$message({
                        message:res.body,
                        type:'success',
                        duration:3000
                    });
                });
            });
        },
        disconnect:function(){
            if (this.stompClient) {
                this.stompClient.disconnect()
            }
        }
    }
};
</script>

3、退出登录时调用disconnect方法断开连接