java代码发送HTTP Post请求

下面是实现类

package com.common.action;



import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLDecoder;

import org.apache.log4j.Logger;



public class Test {

	

	Logger log = Logger.getLogger(RecvReportActionTest.class);

	

	private URL url;



    public RecvReportActionTest(String url) throws Exception {

        this.url = new URL(url);

    }



	public String sendPostRequest(String content) throws Exception {

		

		log.info("try to open http connection to: '" + this.url.getPath()

                + ":" + this.url.getPort() + "'");

        HttpURLConnection conn = (HttpURLConnection) this.url.openConnection();

        

        conn.setConnectTimeout(1000);

        conn.setReadTimeout(10000000);

        conn.setDoOutput(true);

        conn.setRequestMethod("POST");

        

        log.info("try to get output stream");

        OutputStream output = conn.getOutputStream();

        

        log.info("try to write '" + content + "'");

        output.write(content.getBytes());

        output.flush();

        output.close();

        

        log.info("try to get input stream");

        BufferedReader reader = new BufferedReader(new InputStreamReader(conn

                .getInputStream()));

        String line;

        StringBuffer buffer = new StringBuffer("");

        

        while ((line = reader.readLine()) != null) {

            buffer.append(line);

        }

        

        String result = buffer.toString();

        log.info("get resposne: '" + result + "'");

        

        result = URLDecoder.decode(result, "UTF-8");

        return result;

    }

	

	public static void main(String[] args){

		String url="http://127.0.0.1:8080/TestServlet";

		

		String content="<data><m_name>Obj1</m_name><r_name>qq</r_name><level>2</level><result>0</result><content>test</content></data>";

		

		try {

			Test test=new Test(url);

			

			String result=test.sendPostRequest(content);

			

			System.out.println(result);

			

		} catch (Exception e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

		

	}

	



}

在servlet端

InputStream ins=null;

ins=request.getInputStream();

if(ins==null|| ins.available()<=0){

	writeReponse(response,"NO Data");

	return null;

}

发现servlet端ins.available()=0
没有接收到数据。
大家帮忙看看，哪里出问题了？