Android HttpConnection 使用

1，从Intent获取网页，发送请求，将网页以流的形式读回来。

1)创建一个URL对象：URL url = new URL("http://www.iteye.com");

2) 获取链接 ：HttpURLConnection conn=(HttpURLConnection )url.openConnection();

3) 设置超时时间：conn.setConnectTimeout(6*1000);

4) 设置允许输入输出：conn.setDoInput(true);conn.setDoOutput(true);

5) 设置请求模式：conn.setRequestMethod("POST");//注意，要大写

6）设置读取超时：conn.setReadTimeout(true);

7)得到网络返回的输入输出流：InputStream/OutputStream ios = conn.getInputStream()/getOutputStream();

8)判断是否连接成功：conn.getResponseCode()!=200  throw new RuntimeException("请求url失败");

注意：

--在对大文件的操作时,要将文件写到SDCard上面,不要直接写到手机内存上.
--操作大文件是,要一遍从网络上读,一遍要往SDCard上面写,减少手机内存的使用.这点很重要,面试经常会被问到.
--对文件流操作完,要记得及时关闭.

 public class HttpConnect {
     private boolean isCancel = false;
     public void setCancel(boolean isCancel) {
         this.isCancel = isCancel;
     }
     public byte[] open(String strUrl, String postData) {
         byte[] data = null;
         InputStream is = null;
         OutputStream os = null;
         ByteArrayOutputStream baos = null;
         HttpURLConnection conn = null;
         try {// 为了测试取消连接
                 // Thread.sleep(5000);
                 // http联网可以用httpClient或java.net.url
             URL url = new URL(strUrl);
             conn = (HttpURLConnection) url.openConnection();
             conn.setDoInput(true);
             conn.setDoOutput(true);
             conn.setConnectTimeout(1000 * 30);
             conn.setReadTimeout(1000 * 30);
             if (Tools.isNull(postData)) {
                 conn.setRequestMethod("GET");
             } else {
                 conn.setRequestMethod("POST");
                 os = conn.getOutputStream();
                 byte[] sendData = postData.getBytes();
                 os.write(sendData);// 将post数据发出去
             }
             if (isCancel) {
                 LogUtil.i("open", "已经取消掉了连接");
                 return null;
             }
             int responseCode = conn.getResponseCode();
             if (responseCode == 200) {
                 is = conn.getInputStream();
                 baos = new ByteArrayOutputStream();
                 byte[] buffer = new byte[1024 * 8];
                 int size = 0;
                 while ((size = is.read(buffer)) >= 1) {
                     baos.write(buffer, 0, size);
                 }
                 data = baos.toByteArray();
             }

         } catch (Exception e) {
             ExceptionUtil.handle(e);
         } finally {
             try {
                 if (is != null) {is.close();}
                 if (os != null) {os.close();}
                 if (baos != null) {baos.close();}
                 conn = null;
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         if (isCancel) {
             LogUtil.i("open", "已经取消掉了连接");
             return null;
         }
         return data;
     }

 }
 参考链接：