android post请求

public class PureNetUtil {

    /**

     * get方法直接调用post方法

     * @param url 网络地址

     * @return 返回网络数据

     */

    public static String get(String url){

        return post(url,null);

    }

    /**

     * 设定post方法获取网络资源,如果参数为null,实际上设定为get方法

     * @param url 网络地址

     * @param param 请求参数键值对

     * @return 返回读取数据

     */

   public static  String post(String  url,Map   param){

        HttpURLConnection conn=null;

        try {

            URL u=new URL(url);

            conn=(HttpURLConnection) u.openConnection();

            StringBuffer sb=null;

            if(param!=null){//如果请求参数不为空

                sb=new StringBuffer();

                /*A URL connection can be used for input and/or output.  Set the DoOutput

                 * flag to true if you intend to use the URL connection for output,

                 * false if not.  The default is false.*/

                //默认为false,post方法需要写入参数,设定true

                conn.setDoOutput(true);

                //设定post方法,默认get

                conn.setRequestMethod("POST");

                //获得输出流

                OutputStream out=conn.getOutputStream();

                //对输出流封装成高级输出流

                BufferedWriter writer=new BufferedWriter(new OutputStreamWriter(out));

                //将参数封装成键值对的形式

                for(Map.Entry s:param.entrySet()){

                    sb.append(s.getKey()).append("=").append(s.getValue()).append("&");

                }

                //将参数通过输出流写入

                writer.write(sb.deleteCharAt(sb.toString().length()-1).toString());

                writer.close();//一定要关闭,不然可能出现参数不全的错误

                sb=null;

            }

            conn.connect();//建立连接

            sb=new StringBuffer();

            //获取连接状态码

            int recode=conn.getResponseCode();

            BufferedReader reader=null;

            if(recode==200){

                //Returns an input stream that reads from this open connection

                //从连接中获取输入流

                InputStream in=conn.getInputStream();

                //对输入流进行封装

                reader=new BufferedReader(new InputStreamReader(in));

                String str=null;

                sb=new StringBuffer();

                //从输入流中读取数据

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

                    sb.append(str).append(System.getProperty("line.separator"));

                }

                //关闭输入流

                reader.close();

                if (sb.toString().length() == 0) {

                    return null;

                }

                return sb.toString().substring(0,

                        sb.toString().length() - System.getProperty("line.separator").length());

            }

        } catch (Exception e) {

            e.printStackTrace();

            return null;

        }finally{

            if(conn!=null)//关闭连接

                conn.disconnect();

        }

        return null;

    }

  

}