java - 使用HttpURLConnection代替HttpPost

我有一个用Java编写的Android应用程序代码。通过使用HttpPost和DefaultHttpClient库。目前，我正在对其进行重新编码，以使用HttpURLConnection替换HttpPost和DefaultHttpClient库，因为已经描述了DefaultHttpClient。
我已经为我的项目完成了一次，并且成功了。

但是在当前项目中，使用HttpURLConnection而不是DefaultHttpClient时，无法从Web服务获得相同的响应。有人能帮我请我在哪里做错吗？

这是旧的代码：

DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
String postParameter = "Param1=" + Value1 + "&Param2="+ Value2+ "&Param3="+Value3;
try {
 httpPost.setEntity(new StringEntity(postParameter));
} catch (Exception e) {
 e.printStackTrace();
}
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity);

这是我的新代码

_Url = new URL(Url);
HttpURLConnection urlconnection = (HttpURLConnection) _Url.openConnection();
urlconnection.setRequestMethod(Type);
urlconnection.setConnectTimeout(Timeout);
urlconnection.setUseCaches(false);
urlconnection.setDoInput(true);
urlconnection.setDoOutput(true);
 String postParameter = "Param1=" + Value1 + "&Param2="+ Value2+ "&Param3="+Value3;
BufferedWriter writer = new BufferedWriter( new OutputStreamWriter(os));
writer.write(postParameter);
writer.flush();
writer.close();
os.close();
urlconnection.connect();

该代码正在运行，没有任何错误，但是Web服务没有给出与旧代码相同的响应。

最佳答案

您没有得到输入流，请尝试以下代码

         try {

                String postParameter = "Param1=" + Value1 + "&Param2="+ Value2+ "&Param3="+Value3;
                URL url = new URL(UrlStr);
                HttpURLConnection urlConnection = (HttpURLConnection) url
                        .openConnection();
                urlConnection.setRequestMethod("POST");
                urlConnection.setRequestProperty("Accept",
                        "application/json");
                urlConnection.setRequestProperty("Content-Type",
                        "application/json");// setting your headers its a json in my case set your appropriate header

                urlConnection.setDoOutput(true);
                urlConnection.connect();// setting your connection

                OutputStream os = null;
                os = new BufferedOutputStream(
                urlConnection.getOutputStream());
                os.write(postParameter.toString().getBytes());
                os.flush();// writing your data which you post


                StringBuffer buffer = new StringBuffer();
                InputStream is = urlConnection.getInputStream();
                BufferedReader br = new BufferedReader(
                        new InputStreamReader(is));
                String line = null;
                while ((line = br.readLine()) != null)
                    buffer.append(line + "\r\n");
                     // reading your response

                is.close();
                urlConnection.disconnect();// close your connection
                return buffer.toString();

            } catch (Exception e) {
            }