使用POST方法发送数据，android studio单例

public class HttpUtil {
    public static void sendPostRequest(String url, String postData) {
        try {
            URL requestUrl = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) requestUrl.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/json");
            connection.setRequestProperty("Accept", "application/json");
            
            connection.setDoOutput(true);
            OutputStream outputStream = connection.getOutputStream();
            outputStream.write(postData.getBytes("UTF-8"));
            outputStream.flush();
            outputStream.close();
            
            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                InputStream inputStream = connection.getInputStream();
                // 解析响应结果
                // ...
                inputStream.close();
            } else {
                // 处理请求失败的情况
                // ...
            }
            
            connection.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

String url = "https://example.com/api";
String postData = "{\"key\":\"value\"}";
HttpUtil.sendPostRequest(url, postData);