1 package com.lixu.listviewrefresh;
 2 
 3 import java.io.BufferedInputStream;
 4 import java.io.ByteArrayOutputStream;
 5 import java.io.InputStream;
 6 import java.net.HttpURLConnection;
 7 import java.net.URL;
 8 
 9 import android.graphics.Bitmap;
10 import android.graphics.BitmapFactory;
11 
12 public class Loadnetimage {
13     // 设置回调机制
14     
15     private OnLoadnetimageListener mOnLoadnetimageListener;
16 
17     public Loadnetimage() {
18 
19     }
20 
21     public interface OnLoadnetimageListener {
22         public void LoadnetimageListener(int count, int total);
23     }
24 
25     public void SetLoadnetimageListener(OnLoadnetimageListener l) {
26         mOnLoadnetimageListener = l;
27     }
28     
29     
30 
31     public Bitmap loadRawDataFromURL(String u) throws Exception {
32         
33         URL url = new URL(u);
34         HttpURLConnection conn = (HttpURLConnection) url.openConnection();
35         // 设置请求的一些常用的参数
36         conn.setReadTimeout(30000);
37         conn.setConnectTimeout(30000);
38         conn.setDoInput(true);
39         conn.connect();
40         // 获取图片总数
41         int total = conn.getContentLength();
42 
43         InputStream is = conn.getInputStream();
44         BufferedInputStream bis = new BufferedInputStream(is);
45 
46         ByteArrayOutputStream baos = new ByteArrayOutputStream();
47         // 缓存2KB
48         final int BUFFER_SIZE = 2 * 1024;
49         final int EOF = -1;
50 
51         int count = 0;
52 
53         int c;
54         byte[] buf = new byte[BUFFER_SIZE];
55 
56         while (true) {
57             c = bis.read(buf);
58             if (c == EOF)
59                 break;
60             // 每次累加到现在为止我们下载了多少数据，以便于后面计算已经下载的数据占了总数量的百分比
61             count = count + c;
62             // 发布最新的数据，更新随后的进度条显示进度使用
63             if (mOnLoadnetimageListener != null)
64                 mOnLoadnetimageListener.LoadnetimageListener(count, total