HttpURLConnection的使用

 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;

 /**
  * Http工具类
  *
  * @author Administrator
  *
  */
 public class HttpUtils {
     /**
      * 网络请求
      * @param urlpath 地址
      * @return
      */
     public static byte[] request(String urlpath) {
         ByteArrayOutputStream baos=null;
         try {
             baos=new ByteArrayOutputStream();
             //1创建URL
             URL url=new URL(urlpath);
             //2调用openConnection()
             HttpURLConnection connection=(HttpURLConnection) url.openConnection();
             //3设置请求参数
             connection.setConnectTimeout(10000);
             connection.setReadTimeout(10000);
             //4建立连接
             connection.connect();
             //5处理响应结果
             if(connection.getResponseCode()==200){
                 InputStream is=connection.getInputStream();
                 byte[] buf=new byte[1024*4];
                 int len=0;
                 while((len=is.read(buf))!=-1){
                     baos.write(buf,0,len);
                 }
                 is.close();
             }
             return baos.toByteArray();
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         return null;
     }
 }