SpringBoot整合SSE技术详解

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.http.ResponseEntity;
import org.springframework.http.concurrent.PushStreamHttpHeaders;
 
import javax.servlet.http.PushBuilder;
import java.io.PrintWriter;
 
@RestController
public class ServerSentEventController {
 
    @GetMapping(value = "/subscribe", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public ResponseEntity<PushBuilder> subscribe() {
        // 获取PushBuilder对象
        PushBuilder pushBuilder = request.getPushBuilder();
        if (pushBuilder != null) {
            // 设置推送内容的URL
            pushBuilder.path("/publish");
            // 设置推送内容的Content-Type
            PushStreamHttpHeaders headers = new PushStreamHttpHeaders();
            headers.setContentType(MediaType.TEXT_EVENT_STREAM);
            // 返回ResponseEntity，包含PushBuilder对象和推送头部信息
            return ResponseEntity.ok()
                    .headers(headers)
                    .body(pushBuilder);
        }
        return ResponseEntity.notFound().build();
    }
 
    @GetMapping("/publish")
    public void publish(PrintWriter writer) {
        // 使用PrintWriter发送SSE数据
        writer.print("data: Hello, Server-Sent Events!\n\n");
        writer.flush(); // 确保消息已经发送
    }
}

这段代码演示了如何在Spring Boot应用中使用Server-Sent Events（SSE）进行服务端推送。/subscribe端点使用PushBuilder来推送/publish端点的内容。/publish端点则使用PrintWriter来发送SSE格式的文本数据。这个例子简单明了地展示了如何使用Spring Boot来实现SSE推送功能。