Android应用的自动升级、更新模块的实现

我们看到很多Android应用都具有自动更新功能，用户一键就可以完成软件的升级更新。得益于Android系统的软件包管理和安装机制，这一功能实现起来相当简单，下面我们就来实践一下。首先给出界面效果


1. 准备知识
在AndroidManifest.xml里定义了每个Android apk的版本标识：
view plaincopy to clipboardprint?<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
      package="com.myapp" 
      android:versionCode="1" 
      android:versionName="1.0.0"> 
<application></application> 
</manifest> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.myapp"
      android:versionCode="1"
      android:versionName="1.0.0">
<application></application>
</manifest>
其中，android:versionCode和android:versionName两个字段分别表示版本代码，版本名称。versionCode是整型数字，versionName是字符串。由于version是给用户看的，不太容易比较大小，升级检查时，可以以检查versionCode为主，方便比较出版本的前后大小。
那么，在应用中如何读取AndroidManifest.xml中的versionCode和versionName呢？可以使用PackageManager的API，参考以下代码：
view plaincopy to clipboardprint?public static int getVerCode(Context context) { 
        int verCode = -1; 
        try { 
            verCode = context.getPackageManager().getPackageInfo( 
                    "com.myapp", 0).versionCode; 
        } catch (NameNotFoundException e) { 
            Log.e(TAG, e.getMessage()); 
        } 
        return verCode; 
    } 
    
    public static String getVerName(Context context) { 
        String verName = ""; 
        try { 
            verName = context.getPackageManager().getPackageInfo( 
                    "com.myapp", 0).versionName; 
        } catch (NameNotFoundException e) { 
            Log.e(TAG, e.getMessage()); 
        } 
        return verName;    
} 
public static int getVerCode(Context context) {
        int verCode = -1;
        try {
            verCode = context.getPackageManager().getPackageInfo(
                    "com.myapp", 0).versionCode;
        } catch (NameNotFoundException e) {
            Log.e(TAG, e.getMessage());
        }
        return verCode;
    }
  
    public static String getVerName(Context context) {
        String verName = "";
        try {
            verName = context.getPackageManager().getPackageInfo(
                    "com.myapp", 0).versionName;
        } catch (NameNotFoundException e) {
            Log.e(TAG, e.getMessage());
        }
        return verName;  
}
或者在AndroidManifest中将android:versionName="1.2.0"写成android:versionName="@string/app_versionName"，然后在values/strings.xml中添加对应字符串，这样实现之后，就可以使用如下代码获得版本名称：
view plaincopy to clipboardprint?public static String getVerName(Context context) { 
        String verName = context.getResources() 
        .getText(R.string.app_versionName).toString(); 
        return verName; 
} 
public static String getVerName(Context context) {
        String verName = context.getResources()
        .getText(R.string.app_versionName).toString();
        return verName;
}
同理，apk的应用名称可以这样获得：
view plaincopy to clipboardprint?public static String getAppName(Context context) { 
        String verName = context.getResources() 
        .getText(R.string.app_name).toString(); 
        return verName; 
} 
public static String getAppName(Context context) {
        String verName = context.getResources()
        .getText(R.string.app_name).toString();
        return verName;
}


2. 流程框架



3. 版本检查
在服务端放置最新版本的apk文件，如：http://localhost/myapp/myapp.apk
同时，在服务端放置对应此apk的版本信息调用接口或者文件，如:http://localhost/myapp/ver.json
ver.json中的内容为：

view plaincopy to clipboardprint?[{"appname":"jtapp12","apkname":"jtapp-12-updateapksamples.apk","verName":1.0.1,"verCode":2}] 
[{"appname":"jtapp12","apkname":"jtapp-12-updateapksamples.apk","verName":1.0.1,"verCode":2}]

然后，在手机客户端上进行版本读取和检查：
view plaincopy to clipboardprint?private boolean getServerVer () { 
        try { 
            String verjson = NetworkTool.getContent(Config.UPDATE_SERVER 
                    + Config.UPDATE_VERJSON); 
            JSONArray array = new JSONArray(verjson); 
            if (array.length() > 0) { 
                JSONObject obj = array.getJSONObject(0); 
                try { 
                    newVerCode = Integer.parseInt(obj.getString("verCode")); 
                    newVerName = obj.getString("verName"); 
                } catch (Exception e) { 
                    newVerCode = -1; 
                    newVerName = ""; 
                    return false; 
                } 
            } 
        } catch (Exception e) { 
            Log.e(TAG, e.getMessage()); 
            return false; 
        } 
        return true; 
    } 
private boolean getServerVer () {
        try {
            String verjson = NetworkTool.getContent(Config.UPDATE_SERVER
                    + Config.UPDATE_VERJSON);
            JSONArray array = new JSONArray(verjson);
            if (array.length() > 0) {
                JSONObject obj = array.getJSONObject(0);
                try {
                    newVerCode = Integer.parseInt(obj.getString("verCode"));
                    newVerName = obj.getString("verName");
                } catch (Exception e) {
                    newVerCode = -1;
                    newVerName = "";
                    return false;
                }
            }
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
            return false;
        }
        return true;
    }

比较服务器和客户端的版本，并进行更新操作。
view plaincopy to clipboardprint?if (getServerVerCode()) { 
         int vercode = Config.getVerCode(this); // 用到前面第一节写的方法  
         if (newVerCode > vercode) { 
             doNewVersionUpdate(); // 更新新版本  
         } else { 
             notNewVersionShow(); // 提示当前为最新版本  
         } 
     }         
   if (getServerVerCode()) {
            int vercode = Config.getVerCode(this); // 用到前面第一节写的方法
            if (newVerCode > vercode) {
                doNewVersionUpdate(); // 更新新版本
            } else {
                notNewVersionShow(); // 提示当前为最新版本
            }
        }        

详细方法：

view plaincopy to clipboardprint?private void notNewVersionShow() { 
    int verCode = Config.getVerCode(this); 
    String verName = Config.getVerName(this); 
    StringBuffer sb = new StringBuffer(); 
    sb.append("当前版本:"); 
    sb.append(verName); 
    sb.append(" Code:"); 
    sb.append(verCode); 
    sb.append(",/n已是最新版,无需更新!"); 
    Dialog dialog = new AlertDialog.Builder(Update.this).setTitle("软件更新") 
            .setMessage(sb.toString())// 设置内容  
            .setPositiveButton("确定",// 设置确定按钮  
                    new DialogInterface.OnClickListener() { 
                        @Override 
                        public void onClick(DialogInterface dialog, 
                                int which) { 
                            finish(); 
                        } 
                    }).create();// 创建  
    // 显示对话框  
    dialog.show(); 
} 
private void doNewVersionUpdate() { 
    int verCode = Config.getVerCode(this); 
    String verName = Config.getVerName(this); 
    StringBuffer sb = new StringBuffer(); 
    sb.append("当前版本:"); 
    sb.append(verName); 
    sb.append(" Code:"); 
    sb.append(verCode); 
    sb.append(", 发现新版本:"); 
    sb.append(newVerName); 
    sb.append(" Code:"); 
    sb.append(newVerCode); 
    sb.append(", 是否更新?"); 
    Dialog dialog = new AlertDialog.Builder(Update.this) 
            .setTitle("软件更新") 
            .setMessage(sb.toString()) 
            // 设置内容  
            .setPositiveButton("更新",// 设置确定按钮  
                    new DialogInterface.OnClickListener() { 
                        @Override 
                        public void onClick(DialogInterface dialog, 
                                int which) { 
                            pBar = new ProgressDialog(Update.this); 
                            pBar.setTitle("正在下载"); 
                            pBar.setMessage("请稍候..."); 
                            pBar.setProgressStyle(ProgressDialog.STYLE_SPINNER); 
                            downFile(Config.UPDATE_SERVER + Config.UPDATE_APKNAME); 
                        } 
                    }) 
            .setNegativeButton("暂不更新", 
                    new DialogInterface.OnClickListener() { 
                        public void onClick(DialogInterface dialog, 
                                int whichButton) { 
                            // 点击"取消"按钮之后退出程序  
                            finish(); 
                        } 
                    }).create();// 创建  
    // 显示对话框  
    dialog.show(); 
} 
private void notNewVersionShow() {
int verCode = Config.getVerCode(this);
String verName = Config.getVerName(this);
StringBuffer sb = new StringBuffer();
sb.append("当前版本:");
sb.append(verName);
sb.append(" Code:");
sb.append(verCode);
sb.append(",/n已是最新版,无需更新!");
Dialog dialog = new AlertDialog.Builder(Update.this).setTitle("软件更新")
.setMessage(sb.toString())// 设置内容
.setPositiveButton("确定",// 设置确定按钮
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
finish();
}
}).create();// 创建
// 显示对话框
dialog.show();
}
private void doNewVersionUpdate() {
int verCode = Config.getVerCode(this);
String verName = Config.getVerName(this);
StringBuffer sb = new StringBuffer();
sb.append("当前版本:");
sb.append(verName);
sb.append(" Code:");
sb.append(verCode);
sb.append(", 发现新版本:");
sb.append(newVerName);
sb.append(" Code:");
sb.append(newVerCode);
sb.append(", 是否更新?");
Dialog dialog = new AlertDialog.Builder(Update.this)
.setTitle("软件更新")
.setMessage(sb.toString())
// 设置内容
.setPositiveButton("更新",// 设置确定按钮
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
pBar = new ProgressDialog(Update.this);
pBar.setTitle("正在下载");
pBar.setMessage("请稍候...");
pBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
downFile(Config.UPDATE_SERVER + Config.UPDATE_APKNAME);
}
})
.setNegativeButton("暂不更新",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
// 点击"取消"按钮之后退出程序
finish();
}
}).create();// 创建
// 显示对话框
dialog.show();
}

4. 下载模块

注，本部分参考了前人的相关实现，见 http://apps.hi.baidu.com/share/detail/24172508

view plaincopy to clipboardprint?void downFile(final String url) { 
    pBar.show(); 
    new Thread() { 
        public void run() { 
            HttpClient client = new DefaultHttpClient(); 
            HttpGet get = new HttpGet(url); 
            HttpResponse response; 
            try { 
                response = client.execute(get); 
                HttpEntity entity = response.getEntity(); 
                long length = entity.getContentLength(); 
                InputStream is = entity.getContent(); 
                FileOutputStream fileOutputStream = null; 
                if (is != null) { 
                    File file = new File( 
                            Environment.getExternalStorageDirectory(), 
                            Config.UPDATE_SAVENAME); 
                    fileOutputStream = new FileOutputStream(file); 
                    byte[] buf = new byte[1024]; 
                    int ch = -1; 
                    int count = 0; 
                    while ((ch = is.read(buf)) != -1) { 
                        fileOutputStream.write(buf, 0, ch); 
                        count += ch; 
                        if (length > 0) { 
                        } 
                    } 
                } 
                fileOutputStream.flush(); 
                if (fileOutputStream != null) { 
                    fileOutputStream.close(); 
                } 
                down(); 
            } catch (ClientProtocolException e) { 
                e.printStackTrace(); 
            } catch (IOException e) { 
                e.printStackTrace(); 
            } 
        } 
    }.start(); 
} 
    void downFile(final String url) {
        pBar.show();
        new Thread() {
            public void run() {
                HttpClient client = new DefaultHttpClient();
                HttpGet get = new HttpGet(url);
                HttpResponse response;
                try {
                    response = client.execute(get);
                    HttpEntity entity = response.getEntity();
                    long length = entity.getContentLength();
                    InputStream is = entity.getContent();
                    FileOutputStream fileOutputStream = null;
                    if (is != null) {
                        File file = new File(
                                Environment.getExternalStorageDirectory(),
                                Config.UPDATE_SAVENAME);
                        fileOutputStream = new FileOutputStream(file);
                        byte[] buf = new byte[1024];
                        int ch = -1;
                        int count = 0;
                        while ((ch = is.read(buf)) != -1) {
                            fileOutputStream.write(buf, 0, ch);
                            count += ch;
                            if (length > 0) {
                            }
                        }
                    }
                    fileOutputStream.flush();
                    if (fileOutputStream != null) {
                        fileOutputStream.close();
                    }
                    down();
                } catch (ClientProtocolException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }

下载完成，通过handler通知主ui线程将下载对话框取消。
view plaincopy to clipboardprint?void down() { 
        handler.post(new Runnable() { 
            public void run() { 
                pBar.cancel(); 
                update(); 
            } 
        }); 
} 
void down() {
        handler.post(new Runnable() {
            public void run() {
                pBar.cancel();
                update();
            }
        });
}    

5. 安装应用
view plaincopy to clipboardprint?void update() { 
    Intent intent = new Intent(Intent.ACTION_VIEW); 
    intent.setDataAndType(Uri.fromFile(new File(Environment 
            .getExternalStorageDirectory(), Config.UPDATE_SAVENAME)), 
            "application/vnd.android.package-archive"); 
    startActivity(intent); 
} 
    void update() {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(new File(Environment
                .getExternalStorageDirectory(), Config.UPDATE_SAVENAME)),
                "application/vnd.android.package-archive");
        startActivity(intent);
    }
如果你将apk应用发布到market上，那么，你会发现market内建了类似的模块，可以自动更新或者提醒你是否更新应用。那么，对于你自己的应用需要自动更新的话，自己内建一个是不是更加方便了呢？本文提到的代码大多是在UpdateActivity.java中实现，为了能够使更新过程更加友好，可以在最初launcher的Activity中建立一个线程，用来检查服务端是否有更新。有更新的时候就启动UpdateActivity，这样的使用体验更加平滑。

本文例程源码查看/下载：
http://code.google.com/p/androidex/source/browse/trunk/jtapp-12-updateapksamples



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http://blog.csdn.net/xjanker2/archive/2011/04/06/6303937.aspx