chiclaim / Androidupdater

App(The main logic of the version update)：

• (The first download is successful, the installation interface pops up) 第一次下载成功，弹出安装界面；

• (The download was successful, the user did not click to install, but pressed the return key. At some point, we used our APP again, and the download will not be re-downloaded, and the installation interface will pop up) 下载成功，用户没有点击安装，而是按了返回键，在某个时候，又再次使用了我们的APP，不会重新下载，弹出安装界面

• (If the download is successful, it is judged whether the package name of the local apk is the same as the current program, and the version number of the local apk is greater than the version of the current program, and if all are satisfied, the installation program is directly started.) 如果下载成功，则判断本地的apk的包名是否和当前程序是相同的，并且本地apk的版本号大于当前程序的版本，如果都满足则直接启动安装程序。

(Download function, Google officially recommends using the DownloadManager service) 下载功能，Google官方推荐使用 DownloadManager 服务。

经过测试的机型

1. 如何使用DownloadManager

FileDownloadManager.java

    public long startDownload(String uri, String title, String description) {
        DownloadManager.Request req = new DownloadManager.Request(Uri.parse(uri));

        req.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI);
        //req.setAllowedOverRoaming(false);

        req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);

        //设置文件的保存的位置[三种方式]
        //第一种
        //file:///storage/emulated/0/Android/data/your-package/files/Download/update.apk
        req.setDestinationInExternalFilesDir(context, Environment.DIRECTORY_DOWNLOADS, "update.apk");
        //第二种
        //file:///storage/emulated/0/Download/update.apk
        //req.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "update.apk");
        //第三种 自定义文件路径
        //req.setDestinationUri()


        // 设置一些基本显示信息
        req.setTitle(title);
        req.setDescription(description);
        req.setMimeType("application/vnd.android.package-archive");

		//加入下载队列
        return dm.enqueue(req);

        //long downloadId = dm.enqueue(req);
        //Log.d("DownloadManager", downloadId + "");
        //dm.openDownloadedFile()
    }

Android自带的DownloadManager模块来下载, 我们通过通知栏知道, 该模块属于系统自带, 它已经帮我们处理了下载失败、重新下载等功能。

2. (How to detect the download is complete, and then start the installation interface) 如何检测下载完成，然后启动安装界面

DownloadManager下载完成后会发出一个广播 android.intent.action.DOWNLOAD_COMPLETE 新建一个广播接收者即可：

public class ApkInstallReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {
            // @TODO SOMETHING
        }
    }
}

3. 完善App更新逻辑

1> 第一次下载成功，弹出安装界面

这个逻辑在ApkInstallReceiver里做即可：

public class ApkInstallReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {
           installApk(context, downloadApkId);
        }
    }
    

    private static void installApk(Context context, long downloadApkId) {
        DownloadManager dManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
        Intent install = new Intent(Intent.ACTION_VIEW);
        Uri downloadFileUri = dManager.getUriForDownloadedFile(downloadApkId);
        if (downloadFileUri != null) {
            Log.d("DownloadManager", downloadFileUri.toString());
            install.setDataAndType(downloadFileUri, "application/vnd.android.package-archive");
            install.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(install);
        } else {
            Log.e("DownloadManager", "download error");
        }
    }
}

2> 如果用户没有点击安装，而是按了返回键

这个时候用户可能没有安装，而是退出了安装界面，用户退出了我们的APP，在某个时候，又再次使用了我们的APP，这个时候我们不应该去下载新版本，而是使用已经下载已经存在本地的APK。

第一次下载的 downloadManager.enqueue(req)会返回一个downloadId，把downloadId保存到本地，用户下次进来的时候，取出保存的downloadId，然后通过downloadId来获取下载的状态信息。

ApkUpdateUtils.java

public static void download(Context context, String url, String title) {
        long downloadId = SpUtils.getInstance(context).getLong(KEY_DOWNLOAD_ID, -1L);
        if (downloadId != -1L) {
            FileDownloadManager fdm = FileDownloadManager.getInstance(context);
            int status = fdm.getDownloadStatus(downloadId);
            if (status == DownloadManager.STATUS_SUCCESSFUL) {
                //启动更新界面
                Uri uri = fdm.getDownloadUri(downloadId);
                if (uri != null) {
                    if (compare(getApkInfo(context, uri.getPath()), context)) {
                        startInstall(context, uri);
                        return;
                    } else {
                        fdm.getDm().remove(downloadId);
                    }
                }
                start(context, url, title);
            } else if (status == DownloadManager.STATUS_FAILED) {
                start(context, url, title);
            } else {
                if (Config.DEV_MODE) {
                    Log.d(TAG, "apk is already downloading");
                }
            }
        } else {
            start(context, url, title);
        }
    }

获取APK包名、版本号

    /**
     * 获取apk程序信息[packageName,versionName...]
     *
     * @param context Context
     * @param path    apk path
     */
    private static PackageInfo getApkInfo(Context context, String path) {
        if (Config.DEV_MODE) {
            Log.d(TAG, "apk download path: " + path);
        }
        PackageManager pm = context.getPackageManager();
        PackageInfo info = pm.getPackageArchiveInfo(path, PackageManager.GET_ACTIVITIES);
        if (info != null) {
            //String packageName = info.packageName;
            //String version = info.versionName;
            //Log.d(TAG, "packageName:" + packageName + ";version:" + version);
            //String appName = pm.getApplicationLabel(appInfo).toString();
            //Drawable icon = pm.getApplicationIcon(appInfo);//得到图标信息
            return info;
        }
        return null;
    }

获取下载完成的APK地址

    /**
     * 获取保存文件的地址
     *
     * @param downloadId an ID for the download, unique across the system.
     *                   This ID is used to make future calls related to this download.
     * @see FileDownloadManager#getDownloadPath(long)
     */
    public Uri getDownloadUri(long downloadId) {
        return dm.getUriForDownloadedFile(downloadId);
    }

    public DownloadManager getDm() {
        return dm;
    }

获取下载状态信息

    public int getDownloadStatus(long downloadId) {
        DownloadManager.Query query = new DownloadManager.Query().setFilterById(downloadId);
        Cursor c = dm.query(query);
        if (c != null) {
            try {
                if (c.moveToFirst()) {
                    return c.getInt(c.getColumnIndexOrThrow(DownloadManager.COLUMN_STATUS));

                }
            } finally {
                c.close();
            }
        }
        return -1;
    }

如果下载失败，则重新下载并且把downloadId存起来。

    private static void start(Context context, String url, String title) {
        long id = FileDownloadManager.getInstance(context).startDownload(url,
                title, "下载完成后点击打开");
        SpUtils.getInstance(context).putLong(KEY_DOWNLOAD_ID, id);
        if (Config.DEV_MODE) {
            Log.d(TAG, "apk start download " + id);
        }
    }

如果下载成功，则判断本地的apk的包名是否和当前程序是相同的，并且本地apk的版本号大于当前程序的版本，如果都满足则直接启动安装程序。

    /**
     * 下载的apk和当前程序版本比较
     *
     * @param apkInfo apk file's packageInfo
     * @param context Context
     * @return 如果当前应用版本小于apk的版本则返回true
     */
    private static boolean compare(PackageInfo apkInfo, Context context) {
        if (apkInfo == null) {
            return false;
        }
        String localPackage = context.getPackageName();
        if (apkInfo.packageName.equals(localPackage)) {
            try {
                PackageInfo packageInfo = context.getPackageManager().getPackageInfo(localPackage, 0);
                if (apkInfo.versionCode > packageInfo.versionCode) {
                    return true;
                } else {
                    if (Config.DEV_MODE) {
                        Log.d(TAG, "apk's versionCode <= app's versionCode");
                    }
                }
            } catch (PackageManager.NameNotFoundException e) {
                e.printStackTrace();
            }
        }
        if (Config.DEV_MODE) {
            Log.d(TAG, "apk's package not match app's package");
        }
        return false;
    }

启动安装界面

    public static void startInstall(Context context, Uri uri) {
        Intent install = new Intent(Intent.ACTION_VIEW);
        install.setDataAndType(uri, "application/vnd.android.package-archive");
        install.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(install);
    }

为了严谨起见，在ApkInstallReceiver里不仅要对downloadId判断，还应当把当前程序和本地apk包名和版本号对比。

3> 如果用户停止了下载服务[也就是下载管理程序]

可以通过如下代码进入 启用/停止 下载管理程序 界面:

    String packageName = "com.android.providers.downloads";
    Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
    intent.setData(Uri.parse("package:" + packageName));
    startActivity(intent);

我们先停止下载管理程序,然后点击demo里的Download 按钮报出如下错误:

Caused by: java.lang.IllegalArgumentException: Unknown URL content://downloads/my_downloads
          at android.content.ContentResolver.insert(ContentResolver.java:1227)
          at android.app.DownloadManager.enqueue(DownloadManager.java:946)
          at com.chiclam.download.FileDownloadManager.startDownload(FileDownloadManager.java:61)
          at com.chiclam.download.ApkUpdateUtils.start(ApkUpdateUtils.java:47)
          at com.chiclam.download.ApkUpdateUtils.download(ApkUpdateUtils.java:42)
          at com.chiclam.download.MainActivity.download(MainActivity.java:34)
          at java.lang.reflect.Method.invoke(Native Method) 
          at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
          at android.view.View.performClick(View.java:5204) 
          at android.view.View$PerformClick.run(View.java:21153) 
          at android.os.Handler.handleCallback(Handler.java:739) 
          at android.os.Handler.dispatchMessage(Handler.java:95) 
          at android.os.Looper.loop(Looper.java:148) 
          at android.app.ActivityThread.main(ActivityThread.java:5417) 
          at java.lang.reflect.Method.invoke(Native Method) 
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

也就是说如果停止了下载管理程序 调用dm.enqueue(req);就会上面的错误,从而程序闪退.

所以在使用该组件的时候,需要判断该组件是否可用:

    private boolean canDownloadState() {
        try {
            int state = this.getPackageManager().getApplicationEnabledSetting("com.android.providers.downloads");

            if (state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED
                    || state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER
                    || state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_UNTIL_USED) {
                return false;
            }

        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

具体详情, 查看代码.