Android 开发工具类 03_HttpUtils

Http 请求的工具类：

1、异步的 Get 请求；

2、异步的 Post 请求；

3、Get 请求，获得返回数据；

4、向指定 URL 发送 POST方法的请求。

 import java.io.BufferedReader;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.net.HttpURLConnection;
 import java.net.URL;

 // Http 请求的工具类
 public class HttpUtils
 {

     private static final int TIMEOUT_IN_MILLIONS = 5000;

     public interface CallBack
     {
         void onRequestComplete(String result);
     }

     /**
      * 异步的 Get 请求
      *
      * @param urlStr
      * @param callBack
      */
     public static void doGetAsyn(final String urlStr, final CallBack callBack)
     {
         new Thread()
         {
             public void run()
             {
                 try
                 {
                     String result = doGet(urlStr);
                     if (callBack != null)
                     {
                         callBack.onRequestComplete(result);
                     }
                 } catch (Exception e)
                 {
                     e.printStackTrace();
                 }

             };
         }.start();
     }

     /**
      * 异步的 Post 请求
      * @param urlStr
      * @param params
      * @param callBack
      * @throws Exception
      */
     public static void doPostAsyn(final String urlStr, final String params,
             final CallBack callBack) throws Exception
     {
         new Thread()
         {
             public void run()
             {
                 try
                 {
                     String result = doPost(urlStr, params);
                     if (callBack != null)
                     {
                         callBack.onRequestComplete(result);
                     }
                 } catch (Exception e)
                 {
                     e.printStackTrace();
                 }

             };
         }.start();

     }

     /**
      * Get 请求，获得返回数据
      *
      * @param urlStr
      * @return
      * @throws Exception
      */
     public static String doGet(String urlStr)
     {
         URL url = null;
         HttpURLConnection conn = null;
         InputStream is = null;
         ByteArrayOutputStream baos = null;
         try
         {
             url = new URL(urlStr);
             conn = (HttpURLConnection) url.openConnection();
             conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
             conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);
             conn.setRequestMethod("GET");
             conn.setRequestProperty("accept", "*/*");
             conn.setRequestProperty("connection", "Keep-Alive");
             if (conn.getResponseCode() == 200)
             {
                 is = conn.getInputStream();
                 baos = new ByteArrayOutputStream();
                 int len = -1;
                 byte[] buf = new byte[128];

                 while ((len = is.read(buf)) != -1)
                 {
                     baos.write(buf, 0, len);
                 }
                 baos.flush();
                 return baos.toString();
             } else
             {
                 throw new RuntimeException(" responseCode is not 200 ... ");
             }

         } catch (Exception e)
         {
             e.printStackTrace();
         } finally
         {
             try
             {
                 if (is != null)
                     is.close();
             } catch (IOException e)
             {
             }
             try
             {
                 if (baos != null)
                     baos.close();
             } catch (IOException e)
             {
             }
             conn.disconnect();
         }

         return null ;

     }

     /**
      * 向指定 URL 发送 POST 方法的请求
      *
      * @param url
      *            发送请求的 URL
      * @param param
      *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
      * @return 所代表远程资源的响应结果
      * @throws Exception
      */
     public static String doPost(String url, String param)
     {
         PrintWriter out = null;
         BufferedReader in = null;
         String result = "";
         try
         {
             URL realUrl = new URL(url);
             // 打开和URL之间的连接
             HttpURLConnection conn = (HttpURLConnection) realUrl
                     .openConnection();
             // 设置通用的请求属性
             conn.setRequestProperty("accept", "*/*");
             conn.setRequestProperty("connection", "Keep-Alive");
             conn.setRequestMethod("POST");
             conn.setRequestProperty("Content-Type",
                     "application/x-www-form-urlencoded");
             conn.setRequestProperty("charset", "utf-8");
             conn.setUseCaches(false);
             // 发送POST请求必须设置如下两行
             conn.setDoOutput(true);
             conn.setDoInput(true);
             conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
             conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);

             if (param != null && !param.trim().equals(""))
             {
                 // 获取URLConnection对象对应的输出流
                 out = new PrintWriter(conn.getOutputStream());
                 // 发送请求参数
                 out.print(param);
                 // flush输出流的缓冲
                 out.flush();
             }
             // 定义BufferedReader输入流来读取URL的响应
             in = new BufferedReader(
                     new InputStreamReader(conn.getInputStream()));
             String line;
             while ((line = in.readLine()) != null)
             {
                 result += line;
             }
         } catch (Exception e)
         {
             e.printStackTrace();
         }
         // 使用finally块来关闭输出流、输入流
         finally
         {
             try
             {
                 if (out != null)
                 {
                     out.close();
                 }
                 if (in != null)
                 {
                     in.close();
                 }
             } catch (IOException ex)
             {
                 ex.printStackTrace();
             }
         }
         return result;
     }
 }