前言

上回说到，利用vite加载不同mode下的配置文件，可以实现不同运行环境下的参数配置。在前端应用中经常使用到Websocket，其地址同样可以在.env中间中配置。

代码

vite.config.ts代码的执行是在createApp之前，不可以在vite.config.ts中使用例如pinia、router等组件。可以使用import.meta.env获取配置文件中的参数

废话少说，直接上代码。

前端

.env.development

# 开发环境配置
NODE_ENV='development'

# 本地服务端口
VITE_PORT=8093

.......

# Websocket服务地址
VITE_WS_URL='ws://localhost:8083'

demo.vue

const wsPath = import.meta.env.VITE_WS_URL + 'ws/demo';
let wsSocket: any;
function wsInit() {
  if (typeof (WebSocket) === 'undefined') {
    console.log("浏览器不支持websocket");
  } else {
    wsSocket = new WebSocket(wsPath);
    wsSocket.onopen = open;
    wsSocket.onerror = error;
    wsSocket.onmessage = getMessage;
  }
}
function open() {
  console.log("websocket连接成功")
}

function error(error: string) {
  console.log("websocket连接错误", error)
}
function getMessage(msg: MessageEvent) {
  let states = msg.data;
  states = JSON.parse(states);
  states.forEach((dataItem: any) => {

  });
}
function send(params: string) {
  wsSocket.send(params)
}

function close(e: any) {
  console.log("websocket连接关闭")
}
onMounted(() => {
  wsInit();
})
onUnmounted(() => {
  wsSocket.onclose = close;
})

后端

Websocket.config.java

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();
    }
}

DemoWebsocketServer.java

import io.micrometer.common.util.StringUtils;
import jakarta.websocket.*;
import jakarta.websocket.server.ServerEndpoint;
import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;

@Slf4j
@Component
@ServerEndpoint(value = "/ws/demo")
public class DemoWebsocketServer {
    private static ConcurrentHashMap<String, DemoWebsocketServer> webSocketMap = new ConcurrentHashMap<>();
    @Getter
    private Session session;

    public String pointsUrl;
    private static StringRedisTemplate stringRedisTemplate;

    @Autowired
    public void setStringRedisTemplate(StringRedisTemplate stringRedisTemplate) {
        DemoWebsocketServer.stringRedisTemplate = stringRedisTemplate;
    }

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        log.info("{}连接成功", this.getSession());
        webSocketMap.put(session.getId(), this);
        sendMessage("");
    }

    @OnMessage
    public void onMessage(String message) {
        // todo 获取前端发送过来的
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        //从set中删除
        webSocketMap.remove(this.getSession().getId());
        log.info("断开连接" + this.getSession());
    }

    /**
     * @param error
     */
    @OnError
    public void onError(Throwable error) {
        if (error.getMessage().contains("Broken pipe")) {
            log.info("客户端突然断开连接");
        } else {
            System.out.println("发生错误");
            error.printStackTrace();
        }
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) {
        synchronized (webSocketMap) {
            if (!StringUtils.isEmpty(this.getSession().getId()) && webSocketMap.containsKey(this.getSession()
                    .getId())) {
                try {
                    webSocketMap.get(this.getSession().getId()).getSession().getBasicRemote().sendText(message);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        DemoWebsocketServer that = (DemoWebsocketServer) o;
        return Objects.equals(session, that.session) && Objects.equals(pointsUrl, that.pointsUrl);
    }

    @Override
    public int hashCode() {
        return Objects.hash(session, pointsUrl);
    }
}