Android 软件自动更新功能的实现

     <p>一个好的应用软件都是需要好的维护，从初出版本到最后精品，这个过程需要版本不停的更新，那么如何让用户第一时间获取最新的应用安装包呢？那么就要求我们从第一个版本就要实现升级模块这一功能。</p>    <p>自 动更新功能的实现原理，就是我们事先和后台协商好一个接口，我们在应用的主Activity里，去访问这个接口，如果需要更新，后台会返回一些数据(比 如，提示语；最新版本的url等)。然后我们给出提示框，用户点击开始下载，下载完成开始覆盖安装程序，这样用户的应用就保持最新的拉。</p>    <p>为了让大家容易理解，我像往常一样准备一个小例子，这里为了方便我就省去了和后台交互部分了。步骤分别如下：</p>    <p>第一步：新建一个Android工程命名为:UpdateDemo.代码结构如下图所示：</p>    <p><img alt="Android 软件自动更新功能的实现！！！" src="https://simg.open-open.com/show/433f2000b9e11fcf68b8a31f5bf1033e.jpg" width="421" height="384" /></p>    <p>第二步：新建一个UpdateManager.java类，负责软件更新功能模块，代码如下：</p>    <pre class="brush:java; toolbar: true; auto-links: false;">package com.tutor.update;  import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL;   import android.app.AlertDialog; import android.app.Dialog; import android.app.AlertDialog.Builder; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.DialogInterface.OnClickListener; import android.net.Uri; import android.os.Handler; import android.os.Message; import android.view.LayoutInflater; import android.view.View; import android.widget.ProgressBar;  public class UpdateManager {   private Context mContext;    //提示语  private String updateMsg = "有最新的软件包哦，亲快下载吧~";    //返回的安装包url  private String apkUrl = "http://softfile.3g.qq.com:8080/msoft/179/24659/43549/qq_hd_mini_1.4.apk";      private Dialog noticeDialog;    private Dialog downloadDialog;   /* 下载包安装路径 */     private static final String savePath = "/sdcard/updatedemo/";          private static final String saveFileName = savePath + "UpdateDemoRelease.apk";      /* 进度条与通知ui刷新的handler和msg常量 */     private ProgressBar mProgress;           private static final int DOWN_UPDATE = 1;          private static final int DOWN_OVER = 2;          private int progress;          private Thread downLoadThread;          private boolean interceptFlag = false;          private Handler mHandler = new Handler(){      public void handleMessage(Message msg) {       switch (msg.what) {    case DOWN_UPDATE:     mProgress.setProgress(progress);     break;    case DOWN_OVER:          installApk();     break;    default:     break;    }      };     };       public UpdateManager(Context context) {   this.mContext = context;  }    //外部接口让主Activity调用  public void checkUpdateInfo(){   showNoticeDialog();  }      private void showNoticeDialog(){   AlertDialog.Builder builder = new Builder(mContext);   builder.setTitle("软件版本更新");   builder.setMessage(updateMsg);   builder.setPositiveButton("下载", new OnClickListener() {       @Override    public void onClick(DialogInterface dialog, int which) {     dialog.dismiss();     showDownloadDialog();       }   });   builder.setNegativeButton("以后再说", new OnClickListener() {       @Override    public void onClick(DialogInterface dialog, int which) {     dialog.dismiss();        }   });   noticeDialog = builder.create();   noticeDialog.show();  }    private void showDownloadDialog(){   AlertDialog.Builder builder = new Builder(mContext);   builder.setTitle("软件版本更新");      final LayoutInflater inflater = LayoutInflater.from(mContext);   View v = inflater.inflate(R.layout.progress, null);   mProgress = (ProgressBar)v.findViewById(R.id.progress);      builder.setView(v);   builder.setNegativeButton("取消", new OnClickListener() {     @Override    public void onClick(DialogInterface dialog, int which) {     dialog.dismiss();     interceptFlag = true;    }   });   downloadDialog = builder.create();   downloadDialog.show();      downloadApk();  }    private Runnable mdownApkRunnable = new Runnable() {    @Override   public void run() {    try {     URL url = new URL(apkUrl);         HttpURLConnection conn = (HttpURLConnection)url.openConnection();     conn.connect();     int length = conn.getContentLength();     InputStream is = conn.getInputStream();          File file = new File(savePath);     if(!file.exists()){      file.mkdir();     }     String apkFile = saveFileName;     File ApkFile = new File(apkFile);     FileOutputStream fos = new FileOutputStream(ApkFile);          int count = 0;     byte buf[] = new byte[1024];          do{                   int numread = is.read(buf);         count += numread;            progress =(int)(((float)count / length) * 100);            //更新进度            mHandler.sendEmptyMessage(DOWN_UPDATE);         if(numread <= 0){           //下载完成通知安装          mHandler.sendEmptyMessage(DOWN_OVER);          break;         }         fos.write(buf,0,numread);        }while(!interceptFlag);//点击取消就停止下载.          fos.close();     is.close();    } catch (MalformedURLException e) {     e.printStackTrace();    } catch(IOException e){     e.printStackTrace();    }       }  };     /**      * 下载apk      * @param url      */    private void downloadApk(){   downLoadThread = new Thread(mdownApkRunnable);   downLoadThread.start();  }   /**      * 安装apk      * @param url      */  private void installApk(){   File apkfile = new File(saveFileName);         if (!apkfile.exists()) {             return;         }             Intent i = new Intent(Intent.ACTION_VIEW);         i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive");          mContext.startActivity(i);    } }</pre>第三步：在MainActivity.java也就是主Activity调用,代码如下:    <pre class="brush:java; toolbar: true; auto-links: false;">package com.tutor.update;  import android.app.Activity; import android.os.Bundle;  public class MainAcitivity extends Activity {        private UpdateManager mUpdateManager;     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);                  //这里来检测版本是否需要更新         mUpdateManager = new UpdateManager(this);         mUpdateManager.checkUpdateInfo();     }      }</pre>第四步：添加程序所用的资源与权限：    <p></p>    <p>下载的时候用到了ProgressBar,所以事先写了一个progress.xml布局文件，代码如下:</p>    <pre class="brush:xml; toolbar: true; auto-links: false;">                    <!--?xml version="1.0" encoding="utf-8"?-->                    <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content">                               <progressbar style="android:attr/progressBarStyleHorizontal;" android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/progress">                          </progressbar>                    </linearlayout></pre>下载的时候用到了网络部分，所以要在AndroidManifest.xml中添加网络权限，代码如下:    <pre class="brush:xml; toolbar: true; auto-links: false;">                    <uses-permission android:name="android.permission.INTERNET"></uses-permission></pre>第五步:运行查看效果如下:    <p></p>    <p><img alt="Android 软件自动更新功能的实现！！！" src="https://simg.open-open.com/show/9a0d9bdbd987f706389aa653b2043820.jpg" width="333" height="366" />     <img alt="Android 软件自动更新功能的实现！！！" src="https://simg.open-open.com/show/16bbf68921d5282238ece87c17bb13ee.jpg" width="329" height="340" /></p>    <p> 图一:提示有最新包                                                                                   图二：点击开始下载</p>    <p><img alt="Android 软件自动更新功能的实现！！！" src="https://simg.open-open.com/show/2562e5129f86d4adae9d8ed23a4fec12.jpg" width="333" height="365" /></p>    <p>图三：下载完开始安装，我这里模拟器空间不足了。</p>    <p>OK~大功告成了，继续看球，阿森纳已经0:1了，希望范大将军救驾！大家晚安~稍后将会为大家分享更多内容，尽请期待！</p>    <a href="/misc/goto?guid=4959220383203991868"><span style="color:#99ff99;font-size:32px;"><strong>源代码点击进入==></strong></span></a>    <p></p>    <p></p> 转自：    <a href="/misc/goto?guid=4959220383423851371" target="_blank">http://blog.csdn.net/android_tutor/article/details/7015986</a>