JAVA：http发布请求

我对以下帖子请求有疑问：

public String postTest(String action,ConnectionParametrData [] parameters) {
        Uri.Builder builder = new Uri.Builder().scheme(scheme).authority(authority).path(action);
        uri = builder.build();
        BufferedReader in = null;
        String ans = null;
        HttpPost request = new HttpPost(uri.toString());
        HttpClient defaultClient = new DefaultHttpClient();
        try {
            request.setHeader("Content-Type","application/x-www-form-urlencoded");
            request.setEntity(new UrlEncodedFormEntity(getValuePairs(parameters)));
            HttpResponse response = defaultClient.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent(),"UTF-8"),8192);
            StringBuffer sb = new StringBuffer("");
            String line = "";
            String newLine = System.getProperty("line.separator");
            while((line = in.readLine()) != null) {
                sb.append(line + newLine);
            }
            ans = sb.toString();
        } catch (UnsupportedEncodingException e) {
            // Todo Auto-generated catch block
            e.printstacktrace();
        } catch (ClientProtocolException e) {
            // Todo Auto-generated catch block
            e.printstacktrace();
        } catch (IOException e) {
            // Todo Auto-generated catch block
            e.printstacktrace();
        }   
        return ans;
    }

当我执行此方法时,服务器抛出错误,告知请求不是发布请求.

但这种方法非常有效：

private String makePost(String action,ConnectionParametrData [] parameters) throws IOException {
        StringBuilder urlBuild = new StringBuilder();
        urlBuild.append(scheme).append("://www.").append(authority).append(action);
        URL url = new URL(urlBuild.toString());
        URLConnection urlConnection = url.openConnection();
        urlConnection.setDoInput(true);
        urlConnection.setDoOutput(true);
        urlConnection.setUseCaches(false);
        urlConnection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");

        DataOutputStream printout = new DataOutputStream(urlConnection.getoutputStream());

        String content = getParameters(parameters);
        printout.writeBytes(content);
        printout.flush();
        printout.close();

        BufferedReader in = null;
        in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()),8192);
        StringBuffer sb = new StringBuffer("");
        String line = "";
        String newLine = System.getProperty("line.separator");
        while((line = in.readLine()) != null) {
            sb.append(line + newLine);
        }
        in.close();
        return sb.toString();
    }

我更喜欢使用HttpClient而不是URLConecction,
有谁知道为什么第一种方法不被批准为POST？