java接收text/event-stream格式数据

怼烎@ 2023-10-09 20:23 9阅读 0赞

### **java接收text/event-stream格式数据,并且解决接收HTTPS会不是流式输出问题** ###

前段时间因为要对接语音转文字接口，对方接口输出的是text/event-stream返回，返回的是流式输出，本人在百度找了好久，一直没有找到关于怎么接收流式返回的文章，可能很多人不清楚流式输出指的是什么，流式输出是和对方建立一个长连接，接口方会一直不断的给我们推送数据，而不用等待对方接口完全输出后在把返回值一次性返回。

**先贴代码**

### **get请求** ###

public String getEventStream(String urlStr, HttpServletResponse response) {
        
            long statr = System.currentTimeMillis();
            log.info("开始请求接口url:{}", urlStr);
            InputStream is = null;
            StringBuffer bu = new StringBuffer();
            try {
        
                URL url = new URL(urlStr);
                URLConnection conn = url.openConnection();
                is = conn.getInputStream();
    
                byte[] b = new byte[1024];
                int len = -1;
                long end = System.currentTimeMillis();
                log.info("接口url:{},请求开始流式输出{}", urlStr, end - statr);
                while ((len = is.read(b)) != -1) {
        
    
                    String line = new String(b, 0, len, "utf-8");
                    // 处理 event stream 数据
                    response.getWriter().write(line);
                    response.getWriter().flush();
                    bu.append(line);
                }
            } catch (IOException e) {
        
                log.error("请求模型接口异常", e);
                throw new BusinessException(ResponseCode.TOPIC_INITIATION_FAILED);
            } finally {
        
                if (!Objects.isNull(is)) {
        
                    try {
        
                        //12.关闭输入流
                        is.close();
                    } catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
            }
            return bu.toString();
        }

**这里的urlStr参数是url加参数，示例：https://baidu.com?text=12345678  
response是因为我需要同样用流式输出文字给前端，如果你不需要返回给前端，可以不用response参数。**

### **post请求** ###

public String postEventStream(String urlStr, String json, HttpServletResponse response) {
        
            long statr = System.currentTimeMillis();
            log.info("开始请求接口url:{},请求参数{}", urlStr,json);
            InputStream is = null;
            //11.读取输入流中的返回值
            StringBuffer bu = new StringBuffer();
            try {
        
                //1.设置URL
                URL url = new URL(urlStr);
                //2.打开URL连接
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                //3.设置请求方式
                conn.setRequestMethod("POST");
                //4.设置Content-Type
                conn.setRequestProperty("Content-Type", "application/json;charset=utf-8");
                //5.设置Accept
                conn.setRequestProperty("Accept", "text/event-stream");
                //6.设置DoOutput
                conn.setDoOutput(true);
                //7.设置DoInput
                conn.setDoInput(true);
                //8.获取输出流
                OutputStream os = conn.getOutputStream();
                //9.写入参数（json格式）
                os.write(json.getBytes("utf-8"));
                os.flush();
                os.close();
                //10.获取输入流
                is = conn.getInputStream();
    
                byte[] bytes = new byte[1024];
                int len = 0;
                long end = System.currentTimeMillis();
                log.info("接口url:{},请求参数{},请求开始流式输出{}", urlStr,json, end - statr);
                while ((len = is.read(bytes)) != -1) {
        
                    String line = new String(bytes, 0, len, "utf-8");
    
                    response.getWriter().write(line);
                    response.getWriter().flush();
                    bu.append(line);
                }
            } catch (IOException e) {
        
                log.error("请求模型接口异常", e);
                throw new BusinessException(ResponseCode.TOPIC_INITIATION_FAILED);
            } finally {
        
                if (!Objects.isNull(is)) {
        
                    try {
        
                        //12.关闭输入流
                        is.close();
                    } catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
    
            }
            return bu.toString();
    
        }

### 第一次写文章，表达不好请谅解，这里使用的jdk版本是1.8，如果对于springboot怎么样返回给前端流式输出有疑问，可以私信问我 ###