public class HttpHelper { 
  String m_url; 
  HttpClient m_HttpClient; 
 
  public HttpHelper(String url) { 
    m_url = url; 
    m_HttpClient = new HttpClient(); 
  } 
 
  public byte[] post(byte[] bytes, String contentType) throws IOException { 
    PostMethod method = new PostMethod(m_url); 
 
    if ((contentType != null) && (contentType.length() > 0)) 
      method.setRequestHeader("Content-type" , contentType); 
    method.setRequestEntity(new ByteArrayRequestEntity(bytes)); 
    int HttpCode = m_HttpClient.executeMethod(method); 
    if (HttpCode != HttpStatus.SC_OK) 
      throw new IOException("Invalid HttpStatus: " + HttpCode); 
    InputStream respStream = method.getResponseBodyAsStream(); 
    int respBodySize = respStream.available(); 
    if (respBodySize <= 0) 
      throw new IOException("Invalid respBodySize: " + respBodySize); 
    byte[] respBuffer = new byte[respBodySize]; 
    if (respStream.read(respBuffer) != respBodySize) 
      throw new IOException("Read respBody Error"); 
    return respBuffer; 
  } 
 
  public String postXml(String str) throws IOException { 
    byte[] reqBuffer = str.getBytes(Charset.forName("UTF-8")); 
    byte[] respBuffer = post(reqBuffer, "application/xml; charset=UTF-8"); 
    String resp = new String(respBuffer, Charset.forName("UTF-8")); 
    return resp; 
  } 
} 

public class HttpHelper { 
  CloseableHttpClient m_HttpClient; 
 
  public HttpHelper() { 
    m_HttpClient = HttpClients.createDefault(); 
  } 
 
  // send bytes and recv bytes 
  public byte[] post(String url, byte[] bytes, String contentType) throws IOException { 
    HttpPost httpPost = new HttpPost(url); 
    httpPost.setEntity(new ByteArrayEntity(bytes)); 
    if (contentType != null) 
      httpPost.setHeader("Content-type", contentType); 
    CloseableHttpResponse httpResponse = m_HttpClient.execute(httpPost); 
    try { 
      HttpEntity entityResponse = httpResponse.getEntity(); 
      int contentLength = (int) entityResponse.getContentLength(); 
      if (contentLength <= 0) 
        throw new IOException("No response"); 
      byte[] respBuffer = new byte[contentLength]; 
      if (entityResponse.getContent().read(respBuffer) != respBuffer.length) 
        throw new IOException("Read response buffer error"); 
      return respBuffer; 
    } finally { 
      httpResponse.close(); 
    } 
  } 
 
  public byte[] post(String url, byte[] bytes) throws IOException { 
    return post(url, bytes, null); 
  } 
 
  public String postXml(String url, String str) throws IOException { 
    byte[] reqBuffer = str.getBytes(Charset.forName("UTF-8")); 
    byte[] respBuffer = post(url, reqBuffer, "application/xml; charset=UTF-8"); 
    String resp = new String(respBuffer, Charset.forName("UTF-8")); 
    return resp; 
  } 
}