Java tutorial
/* * Copyright (C) 2009 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 android.provider; import android.net.Uri; import android.content.ContentProviderClient; import android.content.ContentValues; import android.content.ContentProviderOperation; import android.content.ContentUris; import android.accounts.Account; import android.database.Cursor; import android.os.RemoteException; import android.util.Pair; /** * The ContentProvider contract for associating data with ana data array account. * This may be used by providers that want to store this data in a standard way. */ public class SyncStateContract { public interface Columns extends BaseColumns { /** * A reference to the name of the account to which this data belongs * <P>Type: STRING</P> */ public static final String ACCOUNT_NAME = "account_name"; /** * A reference to the type of the account to which this data belongs * <P>Type: STRING</P> */ public static final String ACCOUNT_TYPE = "account_type"; /** * The sync data associated with this account. * <P>Type: NONE</P> */ public static final String DATA = "data"; } public static class Constants implements Columns { public static final String CONTENT_DIRECTORY = "syncstate"; } public static final class Helpers { private static final String[] DATA_PROJECTION = new String[] { Columns.DATA, Columns._ID }; private static final String SELECT_BY_ACCOUNT = Columns.ACCOUNT_NAME + "=? AND " + Columns.ACCOUNT_TYPE + "=?"; /** * Get the sync state that is associated with the account or null. * @param provider the {@link ContentProviderClient} that is to be used to communicate * with the {@link android.content.ContentProvider} that contains the sync state. * @param uri the uri of the sync state * @param account the {@link Account} whose sync state should be returned * @return the sync state or null if there is no sync state associated with the account * @throws RemoteException if there is a failure communicating with the remote * {@link android.content.ContentProvider} */ public static byte[] get(ContentProviderClient provider, Uri uri, Account account) throws RemoteException { Cursor c = provider.query(uri, DATA_PROJECTION, SELECT_BY_ACCOUNT, new String[] { account.name, account.type }, null); // Unable to query the provider if (c == null) { throw new RemoteException(); } try { if (c.moveToNext()) { return c.getBlob(c.getColumnIndexOrThrow(Columns.DATA)); } } finally { c.close(); } return null; } /** * Assigns the data array as the sync state for the given account. * @param provider the {@link ContentProviderClient} that is to be used to communicate * with the {@link android.content.ContentProvider} that contains the sync state. * @param uri the uri of the sync state * @param account the {@link Account} whose sync state should be set * @param data the byte[] that contains the sync state * @throws RemoteException if there is a failure communicating with the remote * {@link android.content.ContentProvider} */ public static void set(ContentProviderClient provider, Uri uri, Account account, byte[] data) throws RemoteException { ContentValues values = new ContentValues(); values.put(Columns.DATA, data); values.put(Columns.ACCOUNT_NAME, account.name); values.put(Columns.ACCOUNT_TYPE, account.type); provider.insert(uri, values); } public static Uri insert(ContentProviderClient provider, Uri uri, Account account, byte[] data) throws RemoteException { ContentValues values = new ContentValues(); values.put(Columns.DATA, data); values.put(Columns.ACCOUNT_NAME, account.name); values.put(Columns.ACCOUNT_TYPE, account.type); return provider.insert(uri, values); } public static void update(ContentProviderClient provider, Uri uri, byte[] data) throws RemoteException { ContentValues values = new ContentValues(); values.put(Columns.DATA, data); provider.update(uri, values, null, null); } public static Pair<Uri, byte[]> getWithUri(ContentProviderClient provider, Uri uri, Account account) throws RemoteException { Cursor c = provider.query(uri, DATA_PROJECTION, SELECT_BY_ACCOUNT, new String[] { account.name, account.type }, null); if (c == null) { throw new RemoteException(); } try { if (c.moveToNext()) { long rowId = c.getLong(1); byte[] blob = c.getBlob(c.getColumnIndexOrThrow(Columns.DATA)); return Pair.create(ContentUris.withAppendedId(uri, rowId), blob); } } finally { c.close(); } return null; } /** * Creates and returns a ContentProviderOperation that assigns the data array as the * sync state for the given account. * @param uri the uri of the sync state * @param account the {@link Account} whose sync state should be set * @param data the byte[] that contains the sync state * @return the new ContentProviderOperation that assigns the data array as the * account's sync state */ public static ContentProviderOperation newSetOperation(Uri uri, Account account, byte[] data) { ContentValues values = new ContentValues(); values.put(Columns.DATA, data); return ContentProviderOperation.newInsert(uri).withValue(Columns.ACCOUNT_NAME, account.name) .withValue(Columns.ACCOUNT_TYPE, account.type).withValues(values).build(); } /** * Creates and returns a ContentProviderOperation that assigns the data array as the * sync state for the given account. * @param uri the uri of the specific sync state to set * @param data the byte[] that contains the sync state * @return the new ContentProviderOperation that assigns the data array as the * account's sync state */ public static ContentProviderOperation newUpdateOperation(Uri uri, byte[] data) { ContentValues values = new ContentValues(); values.put(Columns.DATA, data); return ContentProviderOperation.newUpdate(uri).withValues(values).build(); } } }