使用SSE流式输出实战记录(Javaweb前后端)

const eventSource = new EventSource('http://localhost:8080/sse/chat');

eventSource.onmessage = function(event) {
    console.log('Received:', event.data);
    // 在这里处理接收到的数据，比如更新UI
};

eventSource.onmessage = function(event) {
    // event.data的结果假设是 '{"name": "Alice", "age": 25}'
    console.log('Received:', event.data); 
    // 如果是JSON格式，解析后 message 是一个对象： { name: "Alice", age: 25 }
    const message = JSON.parse(event.data); 
    // 在这里更新UI或进行其他操作
};

eventSource.addEventListener('customEvent', function(event) {
    console.log('Custom event received:', event.data);
});

eventSource.onerror = function(event) {
    console.error('EventSource failed:', event);
    // 可以在这里实现重连逻辑
};

eventSource.close();

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

package com.itheima.bigdealboot.controller;

import lombok.extern.slf4j.Slf4j;
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.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

@RestController
@RequestMapping("/sse")
@Slf4j
public class SSEController {
    
    @GetMapping(value = "/chat", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public SseEmitter sseChat(){
        SseEmitter emitter = new SseEmitter();

        // 创建一个定时任务
        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
        executor.scheduleAtFixedRate(() -> {
            try {
                // 发送当前时间戳
                emitter.send(System.currentTimeMillis());
            } catch (IOException e) {
                // 处理异常（如客户端关闭连接）
                emitter.completeWithError(e);
            }
        }, 0, 1, TimeUnit.SECONDS); // 每秒发送一次

        // 处理连接关闭
        emitter.onCompletion(() -> executor.shutdown());
        emitter.onTimeout(() -> {
            emitter.complete();
            executor.shutdown();
        });

        return emitter; // 返回SseEmitter实例
    }
}