Android 下载一个apk文件以及打开这个apk文件

下载一个网络文件的函数如下  

Java代码  

1. public static File downLoadFile(String httpUrl) {   

2.             // TODO Auto-generated method stub   

3.             final String fileName = "nq.apk";   

4.             File tmpFile = new File("//sdcard");   

5.             if (!tmpFile.exists()) {   

6.                     tmpFile.mkdir();   

7.             }   

8.             final File file = new File("//sdcard//" + fileName);   

9.             try {   

10.                     URL url = new URL(httpUrl);   

11.                     try {   

12.                             HttpURLConnection conn = (HttpURLConnection) url   

13.                                             .openConnection();   

14.                             InputStream is = conn.getInputStream();   

15.                             FileOutputStream fos = new FileOutputStream(file);   

16.                             byte[] buf = new byte[256];   

17.                             conn.connect();   

18.                             double count = 0;   

19.                             if (conn.getResponseCode() >= 400) {   

20. //                                  Toast.makeText(DownFile.this, "连接超时", Toast.LENGTH_SHORT)   

21. //                                                  .show();   

22.                                 Log.i("time","time exceed");   

23.                             } else {   

24.                                     while (count <= 100) {   

25.                                             if (is != null) {   

26.                                                     int numRead = is.read(buf);   

27.                                                     if (numRead <= 0) {   

28.                                                             break;   

29.                                                     } else {   

30.                                                             fos.write(buf, 0, numRead);   

31.                                                     }   

32.                                             } else {   

33.                                                     break;   

34.                                             }   

35.                                     }   

36.                             }   

37.                             conn.disconnect();   

38.                             fos.close();   

39.                             is.close();   

40.                     } catch (IOException e) {   

41.                             // TODO Auto-generated catch block   

42.                             e.printStackTrace();   

43.                     }   

44.             } catch (MalformedURLException e) {   

45.                     // TODO Auto-generated catch block   

46.                     e.printStackTrace();   

47.             }   

48.             return file;   

49.     }    

   如果是一个apk文件，打开并且安装的函数为 

Java代码  

1. private void openFile(File file) {   

2.         // TODO Auto-generated method stub   

3.         Log.e("OpenFile", file.getName());   

4.         Intent intent = new Intent();   

5.         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);   

6.         intent.setAction(android.content.Intent.ACTION_VIEW);   

7.         intent.setDataAndType(Uri.fromFile(file),   

8.                         "application/vnd.android.package-archive");   

9.         startActivity(intent);   

10. }