Android应用开发之自动更新不用愁

转摘自:http://blog.csdn.net/leverage_1229/article/details/9034365

今天我们学习如何实现Android应用的自动更新版本功能，这是在各种语言编写的应用中都会经常遇到的情景。当我们的应用检测到网络上有新版本发布时，系统会提示是否下载新版本应用，当新版本应用下载完毕后，系统会自动安装下载的新版本应用（或跳转到相关安装页面询问）。我们将下载的应用存放在sdcard中，由于整个流程涉及对sdcard的读写操作，所以要赋给我们应用读写外存的权限。下面给出该场景的案例：

一、案例技术要点

1.程序清单文件中需要配置如下权限：

访问网络

 <uses-permission android:name="android.permission.INTERNET"/>

读取sdcard

 <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

写入sdcard

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

2.创建一个HttpURLConnection连接，从网络下载新版本应用到本地

3.创建一个ProgressBar下载进度条，实时显示下载应用的进度

4.应用下载完毕后，构建Intent跳转至其安装页面，该Intent的配置如下：

Action：Intent.ACTION_VIEW

DataAndType：Uri.parse("file://" + appFile.toString())，"application/vnd.android.package-archive"

二、案例代码陈列

AndroidManifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="cn.lynn.autoupdate"
     android:versionCode="1"
     android:versionName="1.0" >

     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="15" />
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <application
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name" >
         <activity
             android:name=".AutoUpdateMainActivity"
             android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
     </application>

 </manifest>

strings.xml

 <resources>
     <string name="app_name">Android实现应用自动更新</string>
 </resources>

main.xml

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent" >

     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" />

 </LinearLayout>

下载进度条布局文件：progressBar.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">

     <ProgressBar
         android:id="@+id/progressBar"
         style="?android:attr/progressBarStyleHorizontal"
         android:layout_width="match_parent"
         android:layout_height="wrap_content" />

 </LinearLayout>

AutoUpdateMainActivity.java

 package cn.lynn.autoupdate;

 import android.app.Activity;
 import android.os.Bundle;

 public class AutoUpdateMainActivity extends Activity {
     private UpdateAppManager updateManager;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);

         updateManager = new UpdateAppManager(this);
         updateManager.checkUpdateInfo();
     }

 }

UpdateAppManager.java

 package cn.lynn.autoupdate;

 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;

 import android.app.AlertDialog;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Environment;
 import android.os.Handler;
 import android.os.Message;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.ProgressBar;

 public class UpdateAppManager {
     // 文件分隔符
     private static final String FILE_SEPARATOR = "/";
     // 外存sdcard存放路径
     private static final String FILE_PATH = Environment.getExternalStorageDirectory() + FILE_SEPARATOR +"autoupdate" + FILE_SEPARATOR;
     // 下载应用存放全路径
     private static final String FILE_NAME = FILE_PATH + "autoupdate.apk";
     // 更新应用版本标记
     private static final int UPDARE_TOKEN = 0x29;
     // 准备安装新版本应用标记
     private static final int INSTALL_TOKEN = 0x31;

     private Context context;
     private String message = "检测到本程序有新版本发布，建议您更新！";
     // 以华为天天聊hotalk.apk为例
     private String spec = "http://222.42.1.209:81/1Q2W3E4R5T6Y7U8I9O0P1Z2X3C4V5B/mt.hotalk.com:8080/release/hotalk1.9.17.0088.apk";
     // 下载应用的对话框
     private Dialog dialog;
     // 下载应用的进度条
     private ProgressBar progressBar;
     // 进度条的当前刻度值
     private int curProgress;
     // 用户是否取消下载
     private boolean isCancel;

     public UpdateAppManager(Context context) {
         this.context = context;
     }

     private final Handler handler = new Handler(){
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {
             case UPDARE_TOKEN:
                 progressBar.setProgress(curProgress);
                 break;

             case INSTALL_TOKEN:
                 installApp();
                 break;
             }
         }
     };

     /**
      * 检测应用更新信息
      */
     public void checkUpdateInfo() {
         showNoticeDialog();
     }

     /**
      * 显示提示更新对话框
      */
     private void showNoticeDialog() {
         new AlertDialog.Builder(context)
             .setTitle("软件版本更新")
             .setMessage(message)
             .setPositiveButton("下载", new OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                     dialog.dismiss();
                     showDownloadDialog();
                 }
             }).setNegativeButton("以后再说", new OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                     dialog.dismiss();
                 }
             }).create().show();
     }

     /**
      * 显示下载进度对话框
      */
     private void showDownloadDialog() {
         View view = LayoutInflater.from(context).inflate(R.layout.progressbar, null);
         progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
         AlertDialog.Builder builder = new AlertDialog.Builder(context);
         builder.setTitle("软件版本更新");
         builder.setView(view);
         builder.setNegativeButton("取消", new OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                     dialog.dismiss();
                     isCancel = true;
                 }
             });
         dialog = builder.create();
         dialog.show();
         downloadApp();
     }

     /**
      * 下载新版本应用
      */
     private void downloadApp() {
         new Thread(new Runnable() {
             @Override
             public void run() {
                 URL url = null;
                 InputStream in = null;
                 FileOutputStream out = null;
                 HttpURLConnection conn = null;
                 try {
                     url = new URL(spec);
                     conn = (HttpURLConnection) url.openConnection();
                     conn.connect();
                     long fileLength = conn.getContentLength();
                     in = conn.getInputStream();
                     File filePath = new File(FILE_PATH);
                     if(!filePath.exists()) {
                         filePath.mkdir();
                     }
                     out = new FileOutputStream(new File(FILE_NAME));
                     byte[] buffer = new byte[1024];
                     int len = 0;
                     long readedLength = 0l;
                     while((len = in.read(buffer)) != -1) {
                         // 用户点击“取消”按钮，下载中断
                         if(isCancel) {
                             break;
                         }
                         out.write(buffer, 0, len);
                         readedLength += len;
                         curProgress = (int) (((float) readedLength / fileLength) * 100);
                         handler.sendEmptyMessage(UPDARE_TOKEN);
                         if(readedLength >= fileLength) {
                             dialog.dismiss();
                             // 下载完毕，通知安装
                             handler.sendEmptyMessage(INSTALL_TOKEN);
                             break;
                         }
                     }
                     out.flush();
                 } catch (Exception e) {
                     e.printStackTrace();
                 } finally {
                     if(out != null) {
                         try {
                             out.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                     if(in != null) {
                         try {
                             in.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                     if(conn != null) {
                         conn.disconnect();
                     }
                 }
             }
         }).start();
     }

     /**
      * 安装新版本应用
      */
     private void installApp() {
         File appFile = new File(FILE_NAME);
         if(!appFile.exists()) {
             return;
         }
         // 跳转到新版本应用安装页面
         Intent intent = new Intent(Intent.ACTION_VIEW);
         intent.setDataAndType(Uri.parse("file://" + appFile.toString()), "application/vnd.android.package-archive");
         context.startActivity(intent);
     }
 }

三、案例效果展示

   

        新版本应用下载后，sdcard相关存放目录如下：