1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 package com.android.inputmethod.dictionarypack; 18 19 import android.app.DownloadManager; 20 import android.app.DownloadManager.Query; 21 import android.app.DownloadManager.Request; 22 import android.content.Context; 23 import android.database.Cursor; 24 import android.database.sqlite.SQLiteException; 25 import android.os.ParcelFileDescriptor; 26 import android.util.Log; 27 28 import java.io.FileNotFoundException; 29 30 import javax.annotation.Nullable; 31 32 /** 33 * A class to help with calling DownloadManager methods. 34 * 35 * Mostly, the problem here is that most methods from DownloadManager may throw SQL exceptions if 36 * they can't open the database on disk. We want to avoid crashing in these cases but can't do 37 * much more, so this class insulates the callers from these. SQLiteException also inherit from 38 * RuntimeException so they are unchecked :( 39 * While we're at it, we also insulate callers from the cases where DownloadManager is disabled, 40 * and getSystemService returns null. 41 */ 42 public class DownloadManagerWrapper { 43 private final static String TAG = DownloadManagerWrapper.class.getSimpleName(); 44 private final DownloadManager mDownloadManager; 45 DownloadManagerWrapper(final Context context)46 public DownloadManagerWrapper(final Context context) { 47 this((DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE)); 48 } 49 DownloadManagerWrapper(final DownloadManager downloadManager)50 private DownloadManagerWrapper(final DownloadManager downloadManager) { 51 mDownloadManager = downloadManager; 52 } 53 remove(final long... ids)54 public void remove(final long... ids) { 55 try { 56 if (null != mDownloadManager) { 57 mDownloadManager.remove(ids); 58 } 59 } catch (IllegalArgumentException e) { 60 // This is expected to happen on boot when the device is encrypted. 61 } catch (SQLiteException e) { 62 // We couldn't remove the file from DownloadManager. Apparently, the database can't 63 // be opened. It may be a problem with file system corruption. In any case, there is 64 // not much we can do apart from avoiding crashing. 65 Log.e(TAG, "Can't remove files with ID " + ids + " from download manager", e); 66 } 67 } 68 openDownloadedFile(final long fileId)69 public ParcelFileDescriptor openDownloadedFile(final long fileId) throws FileNotFoundException { 70 try { 71 if (null != mDownloadManager) { 72 return mDownloadManager.openDownloadedFile(fileId); 73 } 74 } catch (IllegalArgumentException e) { 75 // This is expected to happen on boot when the device is encrypted. 76 } catch (SQLiteException e) { 77 Log.e(TAG, "Can't open downloaded file with ID " + fileId, e); 78 } 79 // We come here if mDownloadManager is null or if an exception was thrown. 80 throw new FileNotFoundException(); 81 } 82 83 @Nullable query(final Query query)84 public Cursor query(final Query query) { 85 try { 86 if (null != mDownloadManager) { 87 return mDownloadManager.query(query); 88 } 89 } catch (IllegalArgumentException e) { 90 // This is expected to happen on boot when the device is encrypted. 91 } catch (SQLiteException e) { 92 Log.e(TAG, "Can't query the download manager", e); 93 } 94 // We come here if mDownloadManager is null or if an exception was thrown. 95 return null; 96 } 97 enqueue(final Request request)98 public long enqueue(final Request request) { 99 try { 100 if (null != mDownloadManager) { 101 return mDownloadManager.enqueue(request); 102 } 103 } catch (IllegalArgumentException e) { 104 // This is expected to happen on boot when the device is encrypted. 105 } catch (SQLiteException e) { 106 Log.e(TAG, "Can't enqueue a request with the download manager", e); 107 } 108 return 0; 109 } 110 } 111