将C#程序转化成java程序

Question

//创建请求对象
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(PostUrl);
if (httpWebRequest == null)
{
return "";
}
#region 填充httpWebRequest的基本信息
httpWebRequest.ContentType = contentType;
httpWebRequest.Method = "Post";
#endregion
httpWebRequest.ContentLength = data.Length;
try
{
Stream RequestStream = httpWebRequest.GetRequestStream();
RequestStream.Write(data, 0, data.Length);
RequestStream.Close();
#region 接收返回数据
Stream ResponseStream;
string stringResponse = string.Empty;
ResponseStream = httpWebRequest.GetResponse().GetResponseStream();
using (StreamReader sr = new StreamReader(ResponseStream, RequstEncod))
{
stringResponse = sr.ReadToEnd();
}
ResponseStream.Close();
return stringResponse;

        #endregion

    }
    catch (Exception ex)
    {
        return ex.Message;
    }
}