Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package cn.edu.wyu.documentviewer; import static cn.edu.wyu.documentviewer.model.DocumentInfo.getCursorString; import java.io.IOException; import java.util.Set; import org.apache.commons.io.IOUtils; import android.content.ContentProvider; import android.content.ContentResolver; import android.content.ContentValues; import android.content.Context; import android.content.Intent; import android.content.UriMatcher; import android.content.pm.ResolveInfo; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.net.Uri; import android.os.Bundle; import android.provider.DocumentsContract; import android.provider.DocumentsContract.Document; import android.provider.DocumentsContract.Root; import android.text.format.DateUtils; import android.util.Log; import cn.edu.wyu.documentviewer.model.DocumentStack; import cn.edu.wyu.documentviewer.model.DurableUtils; import com.android.internal.util.Predicate; import com.google.common.collect.Sets; public class RecentsProvider extends ContentProvider { private static final String TAG = "RecentsProvider"; private static final long MAX_HISTORY_IN_MILLIS = 45 * DateUtils.DAY_IN_MILLIS; private static final String AUTHORITY = "cn.edu.wyu.documentviewer.recents"; private static final UriMatcher sMatcher = new UriMatcher(UriMatcher.NO_MATCH); private static final int URI_RECENT = 1; private static final int URI_STATE = 2; private static final int URI_RESUME = 3; public static final String METHOD_PURGE = "purge"; public static final String METHOD_PURGE_PACKAGE = "purgePackage"; static { sMatcher.addURI(AUTHORITY, "recent", URI_RECENT); // state/authority/rootId/docId sMatcher.addURI(AUTHORITY, "state/*/*/*", URI_STATE); // resume/packageName sMatcher.addURI(AUTHORITY, "resume/*", URI_RESUME); } public static final String TABLE_RECENT = "recent"; public static final String TABLE_STATE = "state"; public static final String TABLE_RESUME = "resume"; public static class RecentColumns { public static final String KEY = "key"; public static final String STACK = "stack"; public static final String TIMESTAMP = "timestamp"; } public static class StateColumns { public static final String AUTHORITY = "authority"; public static final String ROOT_ID = Root.COLUMN_ROOT_ID; public static final String DOCUMENT_ID = Document.COLUMN_DOCUMENT_ID; public static final String MODE = "mode"; public static final String SORT_ORDER = "sortOrder"; } public static class ResumeColumns { public static final String PACKAGE_NAME = "package_name"; public static final String STACK = "stack"; public static final String TIMESTAMP = "timestamp"; public static final String EXTERNAL = "external"; } public static Uri buildRecent() { return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(AUTHORITY).appendPath("recent") .build(); } public static Uri buildState(String authority, String rootId, String documentId) { return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(AUTHORITY).appendPath("state") .appendPath(authority).appendPath(rootId).appendPath(documentId).build(); } public static Uri buildResume(String packageName) { return new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(AUTHORITY).appendPath("resume") .appendPath(packageName).build(); } private DatabaseHelper mHelper; private static class DatabaseHelper extends SQLiteOpenHelper { private static final String DB_NAME = "recents.db"; private static final int VERSION_INIT = 1; private static final int VERSION_AS_BLOB = 3; private static final int VERSION_ADD_EXTERNAL = 4; private static final int VERSION_ADD_RECENT_KEY = 5; public DatabaseHelper(Context context) { super(context, DB_NAME, null, VERSION_ADD_RECENT_KEY); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE " + TABLE_RECENT + " (" + RecentColumns.KEY + " TEXT PRIMARY KEY ON CONFLICT REPLACE," + RecentColumns.STACK + " BLOB DEFAULT NULL," + RecentColumns.TIMESTAMP + " INTEGER" + ")"); db.execSQL("CREATE TABLE " + TABLE_STATE + " (" + StateColumns.AUTHORITY + " TEXT," + StateColumns.ROOT_ID + " TEXT," + StateColumns.DOCUMENT_ID + " TEXT," + StateColumns.MODE + " INTEGER," + StateColumns.SORT_ORDER + " INTEGER," + "PRIMARY KEY (" + StateColumns.AUTHORITY + ", " + StateColumns.ROOT_ID + ", " + StateColumns.DOCUMENT_ID + ")" + ")"); db.execSQL("CREATE TABLE " + TABLE_RESUME + " (" + ResumeColumns.PACKAGE_NAME + " TEXT NOT NULL PRIMARY KEY," + ResumeColumns.STACK + " BLOB DEFAULT NULL," + ResumeColumns.TIMESTAMP + " INTEGER," + ResumeColumns.EXTERNAL + " INTEGER NOT NULL DEFAULT 0" + ")"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(TAG, "Upgrading database; wiping app data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_RECENT); db.execSQL("DROP TABLE IF EXISTS " + TABLE_STATE); db.execSQL("DROP TABLE IF EXISTS " + TABLE_RESUME); onCreate(db); } } @Override public boolean onCreate() { mHelper = new DatabaseHelper(getContext()); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { final SQLiteDatabase db = mHelper.getReadableDatabase(); switch (sMatcher.match(uri)) { case URI_RECENT: final long cutoff = System.currentTimeMillis() - MAX_HISTORY_IN_MILLIS; return db.query(TABLE_RECENT, projection, RecentColumns.TIMESTAMP + ">" + cutoff, null, null, null, sortOrder); case URI_STATE: final String authority = uri.getPathSegments().get(1); final String rootId = uri.getPathSegments().get(2); final String documentId = uri.getPathSegments().get(3); return db.query( TABLE_STATE, projection, StateColumns.AUTHORITY + "=? AND " + StateColumns.ROOT_ID + "=? AND " + StateColumns.DOCUMENT_ID + "=?", new String[] { authority, rootId, documentId }, null, null, sortOrder); case URI_RESUME: final String packageName = uri.getPathSegments().get(1); return db.query(TABLE_RESUME, projection, ResumeColumns.PACKAGE_NAME + "=?", new String[] { packageName }, null, null, sortOrder); default: throw new UnsupportedOperationException("Unsupported Uri " + uri); } } @Override public String getType(Uri uri) { return null; } @Override public Uri insert(Uri uri, ContentValues values) { final SQLiteDatabase db = mHelper.getWritableDatabase(); final ContentValues key = new ContentValues(); switch (sMatcher.match(uri)) { case URI_RECENT: values.put(RecentColumns.TIMESTAMP, System.currentTimeMillis()); db.insert(TABLE_RECENT, null, values); final long cutoff = System.currentTimeMillis() - MAX_HISTORY_IN_MILLIS; db.delete(TABLE_RECENT, RecentColumns.TIMESTAMP + "<" + cutoff, null); return uri; case URI_STATE: final String authority = uri.getPathSegments().get(1); final String rootId = uri.getPathSegments().get(2); final String documentId = uri.getPathSegments().get(3); key.put(StateColumns.AUTHORITY, authority); key.put(StateColumns.ROOT_ID, rootId); key.put(StateColumns.DOCUMENT_ID, documentId); // Ensure that row exists, then update with changed values db.insertWithOnConflict(TABLE_STATE, null, key, SQLiteDatabase.CONFLICT_IGNORE); db.update(TABLE_STATE, values, StateColumns.AUTHORITY + "=? AND " + StateColumns.ROOT_ID + "=? AND " + StateColumns.DOCUMENT_ID + "=?", new String[] { authority, rootId, documentId }); return uri; case URI_RESUME: values.put(ResumeColumns.TIMESTAMP, System.currentTimeMillis()); final String packageName = uri.getPathSegments().get(1); key.put(ResumeColumns.PACKAGE_NAME, packageName); // Ensure that row exists, then update with changed values db.insertWithOnConflict(TABLE_RESUME, null, key, SQLiteDatabase.CONFLICT_IGNORE); db.update(TABLE_RESUME, values, ResumeColumns.PACKAGE_NAME + "=?", new String[] { packageName }); return uri; default: throw new UnsupportedOperationException("Unsupported Uri " + uri); } } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { throw new UnsupportedOperationException("Unsupported Uri " + uri); } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { throw new UnsupportedOperationException("Unsupported Uri " + uri); } @Override public Bundle call(String method, String arg, Bundle extras) { if (METHOD_PURGE.equals(method)) { // Purge references to unknown authorities final Intent intent = new Intent(DocumentsContract.PROVIDER_INTERFACE); final Set<String> knownAuth = Sets.newHashSet(); for (ResolveInfo info : getContext().getPackageManager().queryIntentContentProviders(intent, 0)) { knownAuth.add(info.providerInfo.authority); } purgeByAuthority(new Predicate<String>() { @Override public boolean apply(String authority) { // Purge unknown authorities return !knownAuth.contains(authority); } }); return null; } else if (METHOD_PURGE_PACKAGE.equals(method)) { // Purge references to authorities in given package final Intent intent = new Intent(DocumentsContract.PROVIDER_INTERFACE); intent.setPackage(arg); final Set<String> packageAuth = Sets.newHashSet(); for (ResolveInfo info : getContext().getPackageManager().queryIntentContentProviders(intent, 0)) { packageAuth.add(info.providerInfo.authority); } if (!packageAuth.isEmpty()) { purgeByAuthority(new Predicate<String>() { @Override public boolean apply(String authority) { // Purge authority matches return packageAuth.contains(authority); } }); } return null; } else { return super.call(method, arg, extras); } } /** * Purge all internal data whose authority matches the given * {@link Predicate}. */ private void purgeByAuthority(Predicate<String> predicate) { final SQLiteDatabase db = mHelper.getWritableDatabase(); final DocumentStack stack = new DocumentStack(); Cursor cursor = db.query(TABLE_RECENT, null, null, null, null, null, null); try { while (cursor.moveToNext()) { try { final byte[] rawStack = cursor.getBlob(cursor.getColumnIndex(RecentColumns.STACK)); DurableUtils.readFromArray(rawStack, stack); if (stack.root != null && predicate.apply(stack.root.authority)) { final String key = getCursorString(cursor, RecentColumns.KEY); db.delete(TABLE_RECENT, RecentColumns.KEY + "=?", new String[] { key }); } } catch (IOException ignored) { } } } finally { //IoUtils.closeQuietly(cursor); IOUtils.closeQuietly(cursor); } cursor = db.query(TABLE_STATE, new String[] { StateColumns.AUTHORITY }, null, null, StateColumns.AUTHORITY, null, null); try { while (cursor.moveToNext()) { final String authority = getCursorString(cursor, StateColumns.AUTHORITY); if (predicate.apply(authority)) { db.delete(TABLE_STATE, StateColumns.AUTHORITY + "=?", new String[] { authority }); Log.d(TAG, "Purged state for " + authority); } } } finally { //IoUtils.closeQuietly(cursor); IOUtils.closeQuietly(cursor); } cursor = db.query(TABLE_RESUME, null, null, null, null, null, null); try { while (cursor.moveToNext()) { try { final byte[] rawStack = cursor.getBlob(cursor.getColumnIndex(ResumeColumns.STACK)); DurableUtils.readFromArray(rawStack, stack); if (stack.root != null && predicate.apply(stack.root.authority)) { final String packageName = getCursorString(cursor, ResumeColumns.PACKAGE_NAME); db.delete(TABLE_RESUME, ResumeColumns.PACKAGE_NAME + "=?", new String[] { packageName }); } } catch (IOException ignored) { } } } finally { //IoUtils.closeQuietly(cursor); IOUtils.closeQuietly(cursor); } } }