java发送媒体类型为multipart/form-data的请求

public static String sendMultipartFormDataPostRequest(String urlString, String data) throws IOException {String fullUrl = urlString + "?" + data;log.info("完整请求路径为{}", fullUrl);URL url = new URL(fullUrl);HttpURLConnection connection = null;try {connection = (HttpURLConnection) url.openConnection();// 设置请求方法为POSTconnection.setRequestMethod("POST");// 允许输入输出流connection.setDoInput(true);connection.setDoOutput(true);// 设置请求头信息connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + "*****");// 创建请求体输出流
//            OutputStream outputStream = connection.getOutputStream();
//            PrintWriter writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8), true);// 添加请求体结束边界
//            writer.flush();// 关闭流
//            writer.close();
//            outputStream.close();// 发送请求并获取响应int responseCode = connection.getResponseCode();String responseMessage = connection.getResponseMessage();// 输出响应结果log.info("Response Code: {} Response Message: {}" , responseCode, responseMessage);BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));String inputLine;StringBuilder response = new StringBuilder();while ((inputLine = in.readLine()) != null) {response.append(inputLine);}in.close();return response.toString();} catch (Exception e) {throw e;} finally {// 关闭连接if (connection != null) {connection.disconnect();}}}

数据可以和get请求一样用&分隔key=value的形式拼接到地址后面