使用AsyncTask实现Android应用自动更新(转）

2021-08-04 01:22:16

我所开发应用不是面向大众的应用,所以无法放到应用市场去让大家下载,然后通过应用市场更新.所以我必要做一个应用自动更新功能.但是不难,Thanks to下面这篇博客:

Android应用自动更新功能的实现！！！

如果你是以前没有做过此类功能,建议你先看上面的文章.然后再来看我的.因为我也是参考了上面的实现.


  其实这个自动更新功能大体就是两个三个步骤:

   (1)检查更新

   (2)下载更新

  (3)安装更新  

    检查更新和下载更新其实可以算是一步.因为都比较简单,都是主要是下载.

    1) 当你有新的版本发布时,在一个位置放一个更新的文件.

里面到少放有最新应用的版本号.然后你拿当前应用的版本号和服务器上的版本号对比,就知道要不要下载更新了.

   2 ) 下载这个过程,对于Java来说不是什么难事,因为Java提供了丰富的API.更何况Android内置了HttpClient可用.

   3) 这个,安装过程,其实就是使用一个打开查看此下载文件的 Intent.


  这时需要考虑的是文件下载后放到哪里,安全否.:

 一般就是先检测SD卡.然后选择一个合适的目录.

 

01 private void checkUpdate() {
02  
03     RequestFileInfo requestFileInfo = new RequestFileInfo();
04     requestFileInfo.fileUrl = "http://www.waitab.com/demo/demo.apk";
05     String status = Environment.getExternalStorageState();
06     if (!Environment.MEDIA_MOUNTED.equals(status)) {
07         ToastUtils.showFailure(getApplicationContext(),
08                 "SDcard cannot use!");
09         return;
10     }
11     requestFileInfo.saveFilePath = Environment
12             .getExternalStoragePublicDirectory(
13                     Environment.DIRECTORY_DOWNLOADS).getAbsolutePath();
14     requestFileInfo.saveFileName = "DiTouchClient.apk";
15     showHorizontalFragmentDialog(R.string.title_wait,
16             R.string.title_download_update);
17     new DownlaodUpdateTask().execute(requestFileInfo);
18  
19 }

 


上面的进度条显示我已经封装好的了.showHorizontalFragmentDialog()

显然我使用了android-support-v4兼容包来使用Fragment的.


  在进度条中有显示,下载文件大小,已经下载了多少.速度等信息.

   由于涉及到网络操作.所以把这整个逻辑放在AsyncTask中. 

代码如下:

 

001 private class DownlaodUpdateTask extends
002         AsyncTask<RequestFileInfo, ProgressValue, BasicCallResult> {
003  
004     @Override
005     protected BasicCallResult doInBackground(RequestFileInfo... params) {
006         final RequestFileInfo req = params[0];
007         String apkFileName = "";
008         try {
009             URL url = new URL(req.fileUrl); // throw MalformedURLException
010             HttpURLConnection conn = (HttpURLConnection) url
011                     .openConnection();// throws IOException
012             Log.i(TAG, "response code:" + conn.getResponseCode());
013             // 1检查网络连接性
014             if (HttpURLConnection.HTTP_OK != conn.getResponseCode()) {
015                 return new BasicCallResult(
016                         "Can not connect to the update Server! ", false);
017             }
018             int length = conn.getContentLength();
019             double total = StringUtils.bytes2M(length);
020             InputStream is = conn.getInputStream();
021             File path = new File(req.saveFilePath);
022             if (!path.exists())
023                 path.mkdir();
024             File apkFile = new File(req.saveFilePath, req.saveFileName);
025             apkFileName = apkFile.getAbsolutePath();
026             FileOutputStream fos = new FileOutputStream(apkFile);
027             ProgressValue progressValue = new ProgressValue(0, " downlaod…");
028             int count = 0;
029             long startTime, endTime;
030             byte buffer[] = new byte[1024];
031             do {
032                 startTime = System.currentTimeMillis();
033                 int numread = is.read(buffer);
034                 endTime = System.currentTimeMillis();
035                 count += numread;
036                 if (numread <= 0) {
037                     // publish end
038                     break;
039                 }
040                 fos.write(buffer, 0, numread);
041  
042                 double kbPerSecond = Math
043                         .ceil((endTime - startTime) / 1000f);
044                 double current = StringUtils.bytes2M(count);
045                 progressValue.message = String.format(
046                         "%.2f M/%.2f M\t\t%.2fKb/S", total, current,
047                         kbPerSecond);
048                 progressValue.progress = (int) (((float) count / length) * DialogUtil.LONG_PROGRESS_MAX);
049                 publishProgress(progressValue);
050  
051             } while (true);
052             fos.flush();
053             fos.close();
054  
055         } catch (MalformedURLException e) {
056             e.printStackTrace();
057             return new BasicCallResult("Wrong url! ", false);
058         } catch (IOException e) {
059             // TODO Auto-generated catch block
060             e.printStackTrace();
061             return new BasicCallResult("Error: " + e.getLocalizedMessage(),
062                     false);
063         }
064         BasicCallResult callResult = new BasicCallResult(
065                 "download finish!", true);
066         callResult.result = apkFileName;
067         return callResult;
068     }
069  
070     @Override
071     protected void onPostExecute(BasicCallResult result) {
072         removeFragmentDialog();
073         if (result.ok) {
074             installApk(result.result);
075         } else {
076             ToastUtils.showFailure(getApplicationContext(), result.message);
077         }
078     }
079  
080     @Override
081     protected void onProgressUpdate(ProgressValue... values) {
082         ProgressValue value = values[0];
083         updateProgressDialog(value);
084  
085     }
086  
087 }
088  
089 /**
090  * 安装更新APK.
091  *
092  * @param fileUri
093  */
094 private void installApk(String fileUri) {
095     Intent intent = new Intent(Intent.ACTION_VIEW);
096     intent.setDataAndType(Uri.parse("file://" + fileUri),
097             "application/vnd.android.package-archive");
098     startActivity(intent);
099     this.finish();
100  
101 }

 



PS:Java中传递或者返回多个值,我常用的办法就是将数据封装到一个对象中去.上面用到的一些封装对象如下:

传递多个值用对象是因为AsyncTask设计让你传递一个对象作为传递参数,所以传递对象也需要这样使用.


 

01 /**
02  * 传递给android 设置进度条对象
03  *
04  * <a href="http://my.oschina.net/arthor" class="referer" target="_blank">@author</a>  banxi1988
05  *
06  */
07 public final class ProgressValue {
08     /**
09      * 需要设置的进度
10      */
11     public int progress;
12     /**
13      * 提示信息
14      */
15     public String message;
16  
17     public ProgressValue(int progress, String message) {
18         super();
19         this.progress = progress;
20         this.message = message;
21     }
22  
23 }

 



基本的调用返回对象:

 

01 public class BasicCallResult {
02     public String message;
03     public boolean ok;
04     public String result;
05  
06     public BasicCallResult(String message, boolean ok) {
07         super();
08         this.message = message;
09         this.ok = ok;
10     }
11  
12 }

 


传递下载相关信息..

 

view sourceprint?
1 public class RequestFileInfo {
2     public String fileUrl;
3     public String saveFilePath;
4     public String saveFileName;
5  

6 }

使用AsyncTask实现Android应用自动更新(转）

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