Android 下載文件 進度條顯示

加入兩個權限

一個是聯網，另一個是讀寫SD卡

1. <uses-permission Android:name="android.permission.INTERNET"></uses-permission>  
2. <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>  

下載地址是本人的另外一台主機，現在當服務器了，路徑可以測試

http://210.30.12.1:8080/mp3/DJ.mp3

1. import java.io.File;  
2. import java.io.FileNotFoundException;  
3. import java.io.FileOutputStream;  
4. import java.io.IOException;  
5. import java.io.InputStream;  
6. import java.io.OutputStream;  
7. import java.io.RandomAccessFile;  
8. import java.net.MalformedURLException;  
9. import java.net.URL;  
10. import java.net.URLConnection;  
11.   
12. import android.app.Activity;  
13. import android.os.Bundle;  
14. import android.os.Environment;  
15. import android.os.Handler;  
16. import android.os.Message;  
17. import android.util.Log;  
18. import android.view.View;  
19. import android.view.View.OnClickListener;  
20. import android.widget.Button;  
21. import android.widget.ProgressBar;  
22. import android.widget.TextView;  
23. import android.widget.Toast;  
24.   
25. public class FileDownProcessBarActivity extends Activity {  
26.     /** Called when the activity is first created. */  
27.     private static final String Path="http://210.30.12.1:8080/mp3/DJ.mp3";  
28.     private ProgressBar progressBar;  
29.     private TextView textView;  
30.     private Button button;  
31.     private int FileLength;  
32.     private int DownedFileLength=0;  
33.     private InputStream inputStream;  
34.     private URLConnection connection;  
35.     private OutputStream outputStream;  
36.     @Override  
37.     public void onCreate(Bundle savedInstanceState) {  
38.         super.onCreate(savedInstanceState);  
39.         setContentView(R.layout.main);  
40.         progressBar=(ProgressBar) findViewById(R.id.progressBar1);  
41.         textView=(TextView) findViewById(R.id.textView2);  
42.         button=(Button) findViewById(R.id.button1);  
43.         button.setOnClickListener(new ButtonListener());  
44.     }  
45.     class ButtonListener implements OnClickListener{  
46.   
47.         @Override  
48.         public void onClick(View v) {  
49.             DownedFileLength=0;  
50.             // TODO Auto-generated method stub   
51.            Thread thread=new Thread(){  
52.              public void run(){  
53.                  try {  
54.                     DownFile(Path);  
55.                 } catch (Exception e) {  
56.                     // TODO: handle exception   
57.                 }  
58.              }  
59.            };  
60.            thread.start();  
61.         }     
62.     }  
63.     private Handler handler=new Handler()  
64.     {  
65.          public void handleMessage(Message msg)  
66.         {  
67.         if (!Thread.currentThread().isInterrupted()) {  
68.             switch (msg.what) {  
69.             case 0:  
70.                 progressBar.setMax(FileLength);  
71.                 Log.i("文件長度----------->", progressBar.getMax()+"");    
72.                 break;  
73.             case 1:  
74.                 progressBar.setProgress(DownedFileLength);  
75.                 int x=DownedFileLength*100/FileLength;  
76.                 textView.setText(x+"%");  
77.                 break;  
78.             case 2:  
79.                 Toast.makeText(getApplicationContext(), "下載完成", Toast.LENGTH_LONG).show();  
80.                 break;  
81.                   
82.             default:  
83.                 break;  
84.             }  
85.         }     
86.         }  
87.            
88.     };  
89.   
90.     private void DownFile(String urlString)  
91.     {  
92.           
93.         /* 
94.          * 連接到服務器 
95.          */  
96.           
97.         try {  
98.              URL url=new URL(urlString);  
99.              connection=url.openConnection();  
100.              if (connection.getReadTimeout()==5) {  
101.                 Log.i("---------->", "當前網絡有問題");  
102.                 // return;   
103.                }  
104.              inputStream=connection.getInputStream();  
105.               
106.         } catch (MalformedURLException e1) {  
107.             // TODO Auto-generated catch block   
108.             e1.printStackTrace();  
109.         } catch (IOException e) {  
110.             // TODO Auto-generated catch block   
111.             e.printStackTrace();  
112.         }  
113.           
114.         /* 
115.          * 文件的保存路徑和和文件名其中Nobody.mp3是在手機SD卡上要保存的路徑，如果不存在則新建 
116.          */  
117.         String savePAth=Environment.getExternalStorageDirectory()+"/DownFile";  
118.         File file1=new File(savePAth);  
119.         if (!file1.exists()) {  
120.             file1.mkdir();  
121.         }  
122.         String savePathString=Environment.getExternalStorageDirectory()+"/DownFile/"+"DJ.mp3";  
123.         File file =new File(savePathString);  
124.         if (!file.exists()) {  
125.             try {  
126.                 file.createNewFile();  
127.             } catch (IOException e) {  
128.                 // TODO Auto-generated catch block   
129.                 e.printStackTrace();  
130.             }     
131.         }  
132.         /* 
133.          * 向SD卡中寫入文件,用Handle傳遞線程 
134.          */  
135.         Message message=new Message();  
136.         try {  
137.             outputStream=new FileOutputStream(file);  
138.             byte [] buffer=new byte[1024*4];  
139.             FileLength=connection.getContentLength();  
140.             message.what=0;  
141.             handler.sendMessage(message);  
142.             while (DownedFileLength<FileLength) {  
143.                 outputStream.write(buffer);  
144.                 DownedFileLength+=inputStream.read(buffer);  
145.                 Log.i("-------->", DownedFileLength+"");  
146.                 Message message1=new Message();  
147.                 message1.what=1;  
148.                 handler.sendMessage(message1);  
149.             }  
150.             Message message2=new Message();  
151.             message2.what=2;  
152.             handler.sendMessage(message2);  
153.         } catch (FileNotFoundException e) {  
154.             // TODO Auto-generated catch block   
155.             e.printStackTrace();  
156.         } catch (IOException e) {  
157.             // TODO Auto-generated catch block   
158.             e.printStackTrace();  
159.         }  
160.     }  
161.         
162. }