Android下载管理DownloadManager功能扩展和bug修改

http://www.trinea.cn/android/android-downloadmanager-pro/

本文主要介绍如何修改Android系统下载管理，以支持更多的功能及部分bug修改和如何编译生效。目前内容包括暂停下载、继续下载、通知设置NotiExtra和NotiClass、wifi切换到3g自动暂停、Bug修改。

PS: 很多童鞋不是自己做rom，所以就算修改了系统源码编译出来的包在其他系统上也不通用
这里推荐DownloadProvider@Github(并不是我的开源项目，我的项目为TrineaAndroidCommon@Github，包含图片缓存，下拉刷新，静默安装等，欢迎关注)，系统下载管理的独立版，可整合进自己的应用，感谢@DONG童鞋提供地址。

下面需要修改的DownloadManager.java所在目录为frameworks/base/core/java/android/app
DownloadInfo.java, DownloadProvider.java,DownloadThread.java文件所在目录为packages/providers/DownloadProvider/src/com/android/providers/downloads

1、暂停、继续下载功能
(1) DownloadProvider类修改

 

Java

 

1	public int update(final Uri uri, final ContentValues values, final String where, final String[] whereArgs)

函数，修改后代码如下(只增加了一行有效代码)：

 

Java

 

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if (Binder.getCallingPid() != Process.myPid()) {     filteredValues = new ContentValues();     copyString(Downloads.Impl.COLUMN_APP_DATA, values, filteredValues);     copyInteger(Downloads.Impl.COLUMN_VISIBILITY, values, filteredValues);     Integer i = values.getAsInteger(Downloads.Impl.COLUMN_CONTROL);     if (i != null) {         filteredValues.put(Downloads.Impl.COLUMN_CONTROL, i);         startService = true;     }       // trinea BEGIN, added by trinea@trinea.cn 2013/03/01     copyInteger(Downloads.Impl.COLUMN_STATUS, values, filteredValues);     // trinea END     copyInteger(Downloads.Impl.COLUMN_CONTROL, values, filteredValues);     copyString(Downloads.Impl.COLUMN_TITLE, values, filteredValues);     copyString(Downloads.Impl.COLUMN_MEDIAPROVIDER_URI, values, filteredValues);     copyString(Downloads.Impl.COLUMN_DESCRIPTION, values, filteredValues);     copyInteger(Downloads.Impl.COLUMN_DELETED, values, filteredValues); } else {

其中以// trinea BEGIN开头，// trinea END结尾为修改部分，下面代码示例同样如此。因为DownloadProvider安全策略对非该进程id的修改会过滤掉COLUMN_STATUS状态，所以我们需要添加该行。

(2) DownloadThread类修改

 

Java

 

1	private void setupDestinationFile(State state, InnerState innerState)

函数中这个注释掉一个else if，如下：

 

Java

 

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// trinea BEGIN, noted by trinea@trinea.cn 2013/03/01 //} else if (mInfo.mETag == null && !mInfo.mNoIntegrity) { //    // This should've been caught upon failure //    if (Constants.LOGVV) { //        Log.d(TAG, "setupDestinationFile() unable to resume download, deleting " //                + state.mFilename); //    } //    f.delete(); //    throw new StopRequestException(Downloads.Impl.STATUS_CANNOT_RESUME, //            "Trying to resume a download that can't be resumed"); // trinea END

上面一段代码表示一个验证过程，可以去掉。

mETag为数据库中的etag字段值，代码中没有解释，感觉是一个验证值，类似hashcode。
mNoIntegrity为数据中no_integrity字段值，表示启动下载的应用程序能否验证下载的文件的完整性。不过坑爹的是对于etag和no_integrity都没有提供设置的接口

(3) DownloadManager类中添加对外接口

DownloadManager中添加暂停、继续接口

 

Java

 

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/** * pause download, added by trinea@trinea.cn 2013/03/01 * * @param ids the IDs of the downloads to be paused * @return the number of downloads actually paused */ public int pauseDownload(long... ids) {     if (ids == null || ids.length == 0) {         // called with nothing to remove!         throw new IllegalArgumentException("input param 'ids' can't be null");     }       ContentValues values = new ContentValues();     values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_PAUSED);     values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_PAUSED_BY_APP);     if (ids.length == 1) {         return mResolver.update(ContentUris.withAppendedId(mBaseUri, ids[0]), values,                 null, null);     }     return mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),             getWhereArgsForIds(ids)); }   /** * resume download, added by trinea@trinea.cn 2013/03/01 * * @param ids the IDs of the downloads to be resumed * @return the number of downloads actually resumed */ public int resumeDownload(long... ids) {     if (ids == null || ids.length == 0) {         // called with nothing to remove!         throw new IllegalArgumentException("input param 'ids' can't be null");     }       ContentValues values = new ContentValues();     values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_RUN);     values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_RUNNING);     if (ids.length == 1) {         return mResolver.update(ContentUris.withAppendedId(mBaseUri, ids[0]), values,                 null, null);     }     return mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),             getWhereArgsForIds(ids)); }

无论是暂停还是继续我们都是同时把Downloads.Impl.COLUMN_CONTROL和Downloads.Impl.COLUMN_STATUS字段进行修改，因为在DownloadInfo的private boolean isReadyToStart(long now)函数中,会对COLUMN_CONTROL字段进行判断，如果是用户手动暂停的话，是不会自动继续的，部分代码如下：

Click To Expand Code

 

之后我们直接调用DownloadManager的pauseDownload和resumeDownload接口即可

PS：也可以试试不做第二步的修改，而将第一步DownloadProvider的update函数修改变为

 

Java

 

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// trinea BEGIN, added by trinea@trinea.cn 2013/03/01 copyInteger(Downloads.Impl.COLUMN_STATUS, values, filteredValues); copyInteger(Downloads.Impl.COLUMN_NO_INTEGRITY, values, filteredValues); // trinea END

第二步修改变为在public int resumeDownload(long… ids)加入

 

Java

 

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values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_RUN); values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_RUNNING); values.put(Downloads.Impl.COLUMN_NO_INTEGRITY, true);

没有亲自试，不过按照逻辑应该也可以。

2、通知栏可以设置NotiExtra和NotiClass

(1) DownloadProvider类中修改private void checkInsertPermissions(ContentValues values)函数

 

Java

 

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values.remove(Downloads.Impl.COLUMN_IS_VISIBLE_IN_DOWNLOADS_UI); values.remove(Downloads.Impl.COLUMN_MEDIA_SCANNED); // BEGIN, added by trinea@trinea.cn 2013/03/01 values.remove(Downloads.Impl.COLUMN_NOTIFICATION_CLASS); values.remove(Downloads.Impl.COLUMN_NOTIFICATION_EXTRAS); // trinea END

在DownloadProvider insert之前会调用checkInsertPermissions检查不能被插入的字段插入，这里我们需要允许这两个字段存在。

(2) DownloadManager.Request添加对外接口

DownloadManager.Request支持setNotiClass、setNotiExtras

 

在Request中添加接口以及允许字段修改。通过允许设置NotiExtra和NotiClass，我们可以给系统传递更丰富的参数，在通知栏点击相应或是DownloadUi中通过broadcast将这些参数传递出来方便应用调用。

3、wifi切换到3g自动暂停
(1) 修改DownloadInfo.java

 

Java

 

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private int checkIsNetworkTypeAllowed(int networkType) {     if (mIsPublicApi) {         final int flag = translateNetworkTypeToApiFlag(networkType);         final boolean allowAllNetworkTypes = mAllowedNetworkTypes == ~0;         if (!allowAllNetworkTypes && (flag & mAllowedNetworkTypes) == 0) {             return NETWORK_TYPE_DISALLOWED_BY_REQUESTOR;         }         // trinea BEGIN         if (mStatus == Downloads.Impl.STATUS_WAITING_FOR_NETWORK                 && flag != DownloadManager.Request.NETWORK_WIFI) {             return NETWORK_TYPE_DISALLOWED_BY_REQUESTOR;         }         // trinea END     }     return checkSizeAllowedForNetwork(networkType); }

表示等待网络时始终只等待wifi

(2) 修改DownloadReceiver.java

 

Java

 

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} else if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {     NetworkInfo info = (NetworkInfo)             intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);     if (info != null && info.isConnected()) {         startService(context);     } } else if (action.equals(Constants.ACTION_RETRY)) {

修改为：

 

Java

 

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} else if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {     NetworkInfo info = (NetworkInfo)             intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);     // trinea BEGIN     /**      * modified by trinea@trinea.cn @2013/04/01, resume download only when network type is wifi      */     if (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI) {         // trinea END         startService(context);     } } else if (action.equals(Constants.ACTION_RETRY)) {

表示只有连接wifi时才唤醒service去检查是否下载

(3) 修改DownloadThread.java

 

Java

 

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/** * Check if the download has been paused or canceled, stopping the request appropriately if it * has been. */ private void checkPausedOrCanceled(State state) throws StopRequestException {     synchronized (mInfo) {         if (mInfo.mControl == Downloads.Impl.CONTROL_PAUSED) {             Xlog.i(Constants.DL_ENHANCE, "DownloadThread: checkPausedOrCanceled: user pause download");             throw new StopRequestException(                     Downloads.Impl.STATUS_PAUSED_BY_APP, "download paused by owner");         }         if (mInfo.mStatus == Downloads.Impl.STATUS_CANCELED) {             throw new StopRequestException(Downloads.Impl.STATUS_CANCELED, "download canceled");         }     }       // if policy has been changed, trigger connectivity check     if (mPolicyDirty) {         // trinea BEGIN         /**          * add by trinea@trinea.cn @2013/04/01, when switched from wifi to 3g, pause all download          */         NetworkInfo info = mSystemFacade.getActiveNetworkInfo(mInfo.mUid);         if (info != null && !info.isConnected()) {             mInfo.mStatus = Downloads.Impl.STATUS_WAITING_FOR_NETWORK;         }         // trinea END         checkConnectivity();     } }

表示如果网络变化并且表示网络断开时，下载状态变为等待网络。

4、Bug修改
(1) 当存储空间不足时，利用DownloadManager下载，只显示通知栏提示，在下载管理UI中不显示
DownloadManager的Cursor runQuery(ContentResolver resolver, String[] projection, Uri baseUri)函数修改如下：

 

Java

 

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if ((mStatusFlags & STATUS_RUNNING) != 0) {     parts.add(statusClause("=", Downloads.Impl.STATUS_RUNNING));     // trinea BEGIN     parts.add(statusClause("=", Downloads.Impl.STATUS_INSUFFICIENT_SPACE_ERROR));     // trinea END }

DownloadManager的CursorTranslator类的private int translateStatus(int status) 函数修改如下：

 

Java

 

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// trinea BEGIN case Downloads.Impl.STATUS_INSUFFICIENT_SPACE_ERROR: // trinea END case Downloads.Impl.STATUS_RUNNING:     return STATUS_RUNNING;

5、编译安装

修改后是需要重新编译的，需同时编译framweork和DownloadProvider。

framework编译命令为：./makeMtk model mm frameworks/base/core/
编译后apk所在路径为out\target\product\model\system\framework\secondary_framework.jar，之后push到system/framework重启即可。编译命令中model为机型，非mtk平台命令有所不同

DownloadProvider编译命令为./makeMtk model mm packages/providers/DownloadProvider/
编译后apk所在路径为out\target\product\model\system\app\DownloadProvider.apk，之后push到system/app即可(可能需要先删除/system/app/目录下的DownloadProvider.odex)