如何用java发送Http的post请求，并传递参数

package utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.net.URLConnection;

public class TestClass {
    public static void main(String[] args) {
        OutputStreamWriter out = null ;
        BufferedReader in = null;  
        StringBuilder result = new StringBuilder(); 
        String url = "http://192.168.0.104:8088/songsController/selectTotalList";
        String sign = "11f5c83b448383cdb34330d5ddc88209";
        try {  
            URL realUrl = new URL(url);  
            // 打开和URL之间的连接  
            URLConnection conn = realUrl.openConnection();  
           //设置通用的请求头属性
            conn.setRequestProperty("accept", "*/*");  
            conn.setRequestProperty("connection", "Keep-Alive");  
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行   否则会抛异常（java.net.ProtocolException: cannot write to a URLConnection if doOutput=false - call setDoOutput(true)）
            conn.setDoOutput(true);  
            conn.setDoInput(true); 
           //获取URLConnection对象对应的输出流并开始发送参数
            out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");  
            //添加参数
            out.write("&songid="+"10800537");
            out.flush();  
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));  
            String line;  
            while ((line = in.readLine()) != null) {  
                result.append(line);  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        }finally {// 使用finally块来关闭输出流、输入流  
            try {  
                if (out != null) {  
                    out.close();  
                }  
                if (in != null) {  
                    in.close();  
                }  
            } catch (IOException ex) {  
                ex.printStackTrace();  
            }  
        }  
       System.out.println(result.toString()); 
    }  

}