import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

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

/**
 * Author tm
 * Date 2023/9/25
 * Version 1.0
 */
@RestController
@RequestMapping(path = "/sysTest/see")
public class SseControllerTest {
    private static Map<String, SseEmitter> sseCache = new ConcurrentHashMap<>();


    /**
     * 前端傳遞標(biāo)識，生成唯一的消息通道
     */
    @GetMapping(path = "subscribe", produces = {MediaType.TEXT_EVENT_STREAM_VALUE})
    public SseEmitter push(String id) throws IOException {
        // 超時時間設(shè)置為3s，用于演示客戶端自動重連
        SseEmitter sseEmitter = new SseEmitter(30000L);
        // 設(shè)置前端的重試時間為1s
        sseEmitter.send(SseEmitter.event().reconnectTime(1000).data("連接成功"));
        sseCache.put(id, sseEmitter);
        System.out.println("add " + id);
        sseEmitter.onTimeout(() -> {
            System.out.println(id + "超時");
            sseCache.remove(id);
        });
        sseEmitter.onCompletion(() -> System.out.println("完成?。?！"));
        return sseEmitter;
    }

    /**
     * 根據(jù)標(biāo)識傳遞信息
     */
    @GetMapping(path = "push")
    public String push(String id, String content) throws IOException {
        SseEmitter sseEmitter = sseCache.get(id);
        if (sseEmitter != null) {
            sseEmitter.send(SseEmitter.event().name("msg").data("后端發(fā)送消息：" + content));
        }
        return "over";
    }

    /**
     * 根據(jù)標(biāo)識移除SseEmitter
     */
    @GetMapping(path = "over")
    public String over(String id) {
        SseEmitter sseEmitter = sseCache.get(id);
        if (sseEmitter != null) {
            sseEmitter.complete();
            sseCache.remove(id);
        }
        return "over";
    }
}

const  initEventSource = ()=>{
  if (typeof (EventSource) !== 'undefined') {
    const evtSource = new EventSource('https://xxx.xxx.x.x/sysTest/see/subscribe?id=002', { withCredentials: true }) // 后端接口，要配置允許跨域?qū)傩?
    // 與事件源的連接剛打開時觸發(fā)
    evtSource.onopen = function(e){
      console.log(e);
    }

    // 當(dāng)從事件源接收到數(shù)據(jù)時觸發(fā)
    evtSource.onmessage = function(e){
      console.log(e);
    }
    // 與事件源的連接無法打開時觸發(fā)
    evtSource.onerror = function(e){
      console.log(e);
      evtSource.close(); // 關(guān)閉連接
    }
    // 也可以偵聽命名事件，即自定義的事件
    evtSource.addEventListener('msg', function(e) {
      console.log(e.data)
    })
  } else {
    console.log('當(dāng)前瀏覽器不支持使用EventSource接收服務(wù)器推送事件!');
  }

  
}

#eventSource
location /es/ {
    proxy_pass  http://請求地址/;
    #必須要設(shè)置當(dāng)前Connection 屬性
    proxy_set_header Connection '';
    proxy_http_version 1.1;
    chunked_transfer_encoding off;
    proxy_buffering off;
    proxy_cache off;
}