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SpringBoot模擬實(shí)現(xiàn)流式輸出效果

更新時(shí)間：2025年03月17日 09:33:53 作者：果殼~

這篇文章主要為大家詳細(xì)介紹了如何使用SpringBoot模擬實(shí)現(xiàn)流式輸出效果,并在前端使用流式接收數(shù)據(jù)并打印,感興趣的小伙伴可以參考一下

后端接口

import cn.hutool.json.JSONUtil;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

@RestController
@RequestMapping("/test")
public class TestController {

    @PostMapping("/stream")
    public ResponseEntity<StreamingResponseBody> streamData() {
        Map<String, String> map = new HashMap<>();
        map.put("content", "內(nèi)容");

        StreamingResponseBody responseBody = outputStream -> {
            try (PrintWriter writer = new PrintWriter(outputStream)) {
                for (int i = 0; i < 10; i++) {
                    map.put("content", "內(nèi)容:" + i);
                    writer.println(JSONUtil.toJsonStr(map));
                    writer.flush();
                    // 模擬一些延遲
                    Thread.sleep(500);
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        };

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.TEXT_PLAIN);
        // 指示這是一個(gè)流式響應(yīng)
        headers.setContentLength(-1L);

        return new ResponseEntity<>(responseBody, headers, HttpStatus.OK);
    }
}

傳統(tǒng)非流式-前端

url = 'http://127.0.0.1:8080/test/stream'
async function getResp(){
	const startTime = performance.now();
	console.log("非流式輸出")
	const resp = await fetch(url,{
		method: 'POST',
		headers: {
			'Content-Type': 'application/json'
		},
		body: JSON.stringify({
			content: '講個(gè)笑話'
		})
	});
	const msg = await resp.text();
	console.log(msg)
	const endTime = performance.now();
	console.log(`執(zhí)行耗時(shí): ${endTime - startTime} ms`);
}
getResp()

測試結(jié)果如下，程序會(huì)等待所有內(nèi)容都返回了，才輸出內(nèi)容

流式-前端

async function getRespStream(){
	console.log("流式輸出")
	const resp = await fetch(url,{
		method: 'POST',
		headers: {
			'Content-Type': 'application/json'
		},
		body: JSON.stringify({
			content: '講個(gè)笑話'
		})
	});
	
  const reader = resp.body.getReader();
	while(1){
		// value 是類型化數(shù)組
		const textDecoder = new TextDecoder()
		const {done,value} = await reader.read();
		if(done){
			break
		}
		const str = textDecoder.decode(value)
		console.log(str)
	}
}
getRespStream()

可以看到后端只要輸出一段內(nèi)容前端就會(huì)打印一段內(nèi)容。