843 lines
35 KiB
Java
843 lines
35 KiB
Java
/*
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* Copyright (C) 2006 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.content;
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import android.content.pm.PackageManager;
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import android.content.pm.PathPermission;
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import android.content.pm.ProviderInfo;
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import android.content.res.AssetFileDescriptor;
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import android.content.res.Configuration;
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import android.database.Cursor;
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import android.database.CursorToBulkCursorAdaptor;
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import android.database.CursorWindow;
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import android.database.IBulkCursor;
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import android.database.IContentObserver;
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import android.database.SQLException;
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import android.net.Uri;
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import android.os.Binder;
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import android.os.Bundle;
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import android.os.ParcelFileDescriptor;
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import android.os.Process;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.util.ArrayList;
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/**
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* Content providers are one of the primary building blocks of Android applications, providing
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* content to applications. They encapsulate data and provide it to applications through the single
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* {@link ContentResolver} interface. A content provider is only required if you need to share
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* data between multiple applications. For example, the contacts data is used by multiple
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* applications and must be stored in a content provider. If you don't need to share data amongst
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* multiple applications you can use a database directly via
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* {@link android.database.sqlite.SQLiteDatabase}.
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*
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* <p>For more information, read <a href="{@docRoot}guide/topics/providers/content-providers.html">Content
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* Providers</a>.</p>
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*
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* <p>When a request is made via
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* a {@link ContentResolver} the system inspects the authority of the given URI and passes the
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* request to the content provider registered with the authority. The content provider can interpret
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* the rest of the URI however it wants. The {@link UriMatcher} class is helpful for parsing
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* URIs.</p>
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*
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* <p>The primary methods that need to be implemented are:
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* <ul>
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* <li>{@link #onCreate} which is called to initialize the provider</li>
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* <li>{@link #query} which returns data to the caller</li>
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* <li>{@link #insert} which inserts new data into the content provider</li>
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* <li>{@link #update} which updates existing data in the content provider</li>
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* <li>{@link #delete} which deletes data from the content provider</li>
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* <li>{@link #getType} which returns the MIME type of data in the content provider</li>
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* </ul></p>
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*
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* <p class="caution">Data access methods (such as {@link #insert} and
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* {@link #update}) may be called from many threads at once, and must be thread-safe.
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* Other methods (such as {@link #onCreate}) are only called from the application
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* main thread, and must avoid performing lengthy operations. See the method
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* descriptions for their expected thread behavior.</p>
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*
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* <p>Requests to {@link ContentResolver} are automatically forwarded to the appropriate
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* ContentProvider instance, so subclasses don't have to worry about the details of
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* cross-process calls.</p>
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*/
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public abstract class ContentProvider implements ComponentCallbacks {
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/*
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* Note: if you add methods to ContentProvider, you must add similar methods to
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* MockContentProvider.
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*/
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private Context mContext = null;
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private int mMyUid;
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private String mReadPermission;
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private String mWritePermission;
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private PathPermission[] mPathPermissions;
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private boolean mExported;
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private Transport mTransport = new Transport();
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/**
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* Construct a ContentProvider instance. Content providers must be
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* <a href="{@docRoot}guide/topics/manifest/provider-element.html">declared
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* in the manifest</a>, accessed with {@link ContentResolver}, and created
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* automatically by the system, so applications usually do not create
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* ContentProvider instances directly.
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*
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* <p>At construction time, the object is uninitialized, and most fields and
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* methods are unavailable. Subclasses should initialize themselves in
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* {@link #onCreate}, not the constructor.
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*
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* <p>Content providers are created on the application main thread at
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* application launch time. The constructor must not perform lengthy
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* operations, or application startup will be delayed.
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*/
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public ContentProvider() {
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}
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/**
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* Constructor just for mocking.
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*
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* @param context A Context object which should be some mock instance (like the
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* instance of {@link android.test.mock.MockContext}).
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* @param readPermission The read permision you want this instance should have in the
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* test, which is available via {@link #getReadPermission()}.
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* @param writePermission The write permission you want this instance should have
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* in the test, which is available via {@link #getWritePermission()}.
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* @param pathPermissions The PathPermissions you want this instance should have
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* in the test, which is available via {@link #getPathPermissions()}.
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* @hide
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*/
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public ContentProvider(
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Context context,
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String readPermission,
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String writePermission,
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PathPermission[] pathPermissions) {
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mContext = context;
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mReadPermission = readPermission;
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mWritePermission = writePermission;
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mPathPermissions = pathPermissions;
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}
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/**
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* Given an IContentProvider, try to coerce it back to the real
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* ContentProvider object if it is running in the local process. This can
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* be used if you know you are running in the same process as a provider,
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* and want to get direct access to its implementation details. Most
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* clients should not nor have a reason to use it.
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*
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* @param abstractInterface The ContentProvider interface that is to be
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* coerced.
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* @return If the IContentProvider is non-null and local, returns its actual
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* ContentProvider instance. Otherwise returns null.
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* @hide
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*/
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public static ContentProvider coerceToLocalContentProvider(
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IContentProvider abstractInterface) {
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if (abstractInterface instanceof Transport) {
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return ((Transport)abstractInterface).getContentProvider();
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}
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return null;
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}
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/**
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* Binder object that deals with remoting.
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*
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* @hide
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*/
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class Transport extends ContentProviderNative {
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ContentProvider getContentProvider() {
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return ContentProvider.this;
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}
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/**
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* Remote version of a query, which returns an IBulkCursor. The bulk
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* cursor should be wrapped with BulkCursorToCursorAdaptor before use.
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*/
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public IBulkCursor bulkQuery(Uri uri, String[] projection,
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String selection, String[] selectionArgs, String sortOrder,
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IContentObserver observer, CursorWindow window) {
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enforceReadPermission(uri);
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Cursor cursor = ContentProvider.this.query(uri, projection,
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selection, selectionArgs, sortOrder);
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if (cursor == null) {
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return null;
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}
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return new CursorToBulkCursorAdaptor(cursor, observer,
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ContentProvider.this.getClass().getName(),
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hasWritePermission(uri), window);
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}
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public Cursor query(Uri uri, String[] projection,
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String selection, String[] selectionArgs, String sortOrder) {
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enforceReadPermission(uri);
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return ContentProvider.this.query(uri, projection, selection,
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selectionArgs, sortOrder);
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}
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public String getType(Uri uri) {
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return ContentProvider.this.getType(uri);
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}
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public Uri insert(Uri uri, ContentValues initialValues) {
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enforceWritePermission(uri);
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return ContentProvider.this.insert(uri, initialValues);
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}
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public int bulkInsert(Uri uri, ContentValues[] initialValues) {
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enforceWritePermission(uri);
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return ContentProvider.this.bulkInsert(uri, initialValues);
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}
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public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
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throws OperationApplicationException {
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for (ContentProviderOperation operation : operations) {
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if (operation.isReadOperation()) {
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enforceReadPermission(operation.getUri());
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}
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if (operation.isWriteOperation()) {
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enforceWritePermission(operation.getUri());
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}
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}
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return ContentProvider.this.applyBatch(operations);
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}
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public int delete(Uri uri, String selection, String[] selectionArgs) {
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enforceWritePermission(uri);
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return ContentProvider.this.delete(uri, selection, selectionArgs);
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}
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public int update(Uri uri, ContentValues values, String selection,
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String[] selectionArgs) {
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enforceWritePermission(uri);
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return ContentProvider.this.update(uri, values, selection, selectionArgs);
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}
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public ParcelFileDescriptor openFile(Uri uri, String mode)
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throws FileNotFoundException {
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if (mode != null && mode.startsWith("rw")) enforceWritePermission(uri);
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else enforceReadPermission(uri);
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return ContentProvider.this.openFile(uri, mode);
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}
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public AssetFileDescriptor openAssetFile(Uri uri, String mode)
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throws FileNotFoundException {
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if (mode != null && mode.startsWith("rw")) enforceWritePermission(uri);
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else enforceReadPermission(uri);
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return ContentProvider.this.openAssetFile(uri, mode);
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}
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/**
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* @hide
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*/
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public Bundle call(String method, String request, Bundle args) {
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return ContentProvider.this.call(method, request, args);
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}
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private void enforceReadPermission(Uri uri) {
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final int uid = Binder.getCallingUid();
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if (uid == mMyUid) {
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return;
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}
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final Context context = getContext();
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final String rperm = getReadPermission();
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final int pid = Binder.getCallingPid();
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if (mExported && (rperm == null
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|| context.checkPermission(rperm, pid, uid)
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== PackageManager.PERMISSION_GRANTED)) {
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return;
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}
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PathPermission[] pps = getPathPermissions();
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if (pps != null) {
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final String path = uri.getPath();
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int i = pps.length;
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while (i > 0) {
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i--;
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final PathPermission pp = pps[i];
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final String pprperm = pp.getReadPermission();
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if (pprperm != null && pp.match(path)) {
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if (context.checkPermission(pprperm, pid, uid)
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== PackageManager.PERMISSION_GRANTED) {
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return;
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}
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}
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}
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}
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if (context.checkUriPermission(uri, pid, uid,
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Intent.FLAG_GRANT_READ_URI_PERMISSION)
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== PackageManager.PERMISSION_GRANTED) {
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return;
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}
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String msg = "Permission Denial: reading "
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+ ContentProvider.this.getClass().getName()
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+ " uri " + uri + " from pid=" + Binder.getCallingPid()
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+ ", uid=" + Binder.getCallingUid()
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+ " requires " + rperm;
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throw new SecurityException(msg);
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}
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private boolean hasWritePermission(Uri uri) {
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final int uid = Binder.getCallingUid();
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if (uid == mMyUid) {
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return true;
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}
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final Context context = getContext();
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final String wperm = getWritePermission();
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final int pid = Binder.getCallingPid();
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if (mExported && (wperm == null
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|| context.checkPermission(wperm, pid, uid)
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== PackageManager.PERMISSION_GRANTED)) {
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return true;
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}
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PathPermission[] pps = getPathPermissions();
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if (pps != null) {
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final String path = uri.getPath();
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int i = pps.length;
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while (i > 0) {
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i--;
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final PathPermission pp = pps[i];
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final String ppwperm = pp.getWritePermission();
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if (ppwperm != null && pp.match(path)) {
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if (context.checkPermission(ppwperm, pid, uid)
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== PackageManager.PERMISSION_GRANTED) {
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return true;
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}
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}
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}
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}
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if (context.checkUriPermission(uri, pid, uid,
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Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
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== PackageManager.PERMISSION_GRANTED) {
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return true;
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}
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return false;
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}
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private void enforceWritePermission(Uri uri) {
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if (hasWritePermission(uri)) {
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return;
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}
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String msg = "Permission Denial: writing "
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+ ContentProvider.this.getClass().getName()
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+ " uri " + uri + " from pid=" + Binder.getCallingPid()
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+ ", uid=" + Binder.getCallingUid()
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+ " requires " + getWritePermission();
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throw new SecurityException(msg);
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}
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}
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/**
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* Retrieves the Context this provider is running in. Only available once
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* {@link #onCreate} has been called -- this will return null in the
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* constructor.
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*/
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public final Context getContext() {
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return mContext;
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}
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/**
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* Change the permission required to read data from the content
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* provider. This is normally set for you from its manifest information
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* when the provider is first created.
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*
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* @param permission Name of the permission required for read-only access.
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*/
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protected final void setReadPermission(String permission) {
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mReadPermission = permission;
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}
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/**
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* Return the name of the permission required for read-only access to
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* this content provider. This method can be called from multiple
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* threads, as described in
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* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
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* Processes and Threads</a>.
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*/
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public final String getReadPermission() {
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return mReadPermission;
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}
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/**
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* Change the permission required to read and write data in the content
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* provider. This is normally set for you from its manifest information
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* when the provider is first created.
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*
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* @param permission Name of the permission required for read/write access.
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*/
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protected final void setWritePermission(String permission) {
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mWritePermission = permission;
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}
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/**
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* Return the name of the permission required for read/write access to
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* this content provider. This method can be called from multiple
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* threads, as described in
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* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
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* Processes and Threads</a>.
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*/
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public final String getWritePermission() {
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return mWritePermission;
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}
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/**
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* Change the path-based permission required to read and/or write data in
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* the content provider. This is normally set for you from its manifest
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* information when the provider is first created.
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*
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* @param permissions Array of path permission descriptions.
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*/
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protected final void setPathPermissions(PathPermission[] permissions) {
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mPathPermissions = permissions;
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}
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/**
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* Return the path-based permissions required for read and/or write access to
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* this content provider. This method can be called from multiple
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* threads, as described in
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* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
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* Processes and Threads</a>.
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*/
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public final PathPermission[] getPathPermissions() {
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return mPathPermissions;
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}
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/**
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* Implement this to initialize your content provider on startup.
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* This method is called for all registered content providers on the
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* application main thread at application launch time. It must not perform
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* lengthy operations, or application startup will be delayed.
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*
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* <p>You should defer nontrivial initialization (such as opening,
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* upgrading, and scanning databases) until the content provider is used
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* (via {@link #query}, {@link #insert}, etc). Deferred initialization
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* keeps application startup fast, avoids unnecessary work if the provider
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* turns out not to be needed, and stops database errors (such as a full
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* disk) from halting application launch.
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*
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* <p>If you use SQLite, {@link android.database.sqlite.SQLiteOpenHelper}
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* is a helpful utility class that makes it easy to manage databases,
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* and will automatically defer opening until first use. If you do use
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* SQLiteOpenHelper, make sure to avoid calling
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* {@link android.database.sqlite.SQLiteOpenHelper#getReadableDatabase} or
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* {@link android.database.sqlite.SQLiteOpenHelper#getWritableDatabase}
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* from this method. (Instead, override
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* {@link android.database.sqlite.SQLiteOpenHelper#onOpen} to initialize the
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* database when it is first opened.)
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*
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* @return true if the provider was successfully loaded, false otherwise
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*/
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public abstract boolean onCreate();
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/**
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* {@inheritDoc}
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* This method is always called on the application main thread, and must
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* not perform lengthy operations.
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*
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* <p>The default content provider implementation does nothing.
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* Override this method to take appropriate action.
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* (Content providers do not usually care about things like screen
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* orientation, but may want to know about locale changes.)
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*/
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public void onConfigurationChanged(Configuration newConfig) {
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}
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/**
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* {@inheritDoc}
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* This method is always called on the application main thread, and must
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* not perform lengthy operations.
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*
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* <p>The default content provider implementation does nothing.
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* Subclasses may override this method to take appropriate action.
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*/
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public void onLowMemory() {
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}
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/**
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* Implement this to handle query requests from clients.
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* This method can be called from multiple threads, as described in
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* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
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* Processes and Threads</a>.
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* <p>
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* Example client call:<p>
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* <pre>// Request a specific record.
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* Cursor managedCursor = managedQuery(
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ContentUris.withAppendedId(Contacts.People.CONTENT_URI, 2),
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projection, // Which columns to return.
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null, // WHERE clause.
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null, // WHERE clause value substitution
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People.NAME + " ASC"); // Sort order.</pre>
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* Example implementation:<p>
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* <pre>// SQLiteQueryBuilder is a helper class that creates the
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// proper SQL syntax for us.
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SQLiteQueryBuilder qBuilder = new SQLiteQueryBuilder();
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// Set the table we're querying.
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qBuilder.setTables(DATABASE_TABLE_NAME);
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// If the query ends in a specific record number, we're
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// being asked for a specific record, so set the
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// WHERE clause in our query.
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if((URI_MATCHER.match(uri)) == SPECIFIC_MESSAGE){
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qBuilder.appendWhere("_id=" + uri.getPathLeafId());
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}
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// Make the query.
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Cursor c = qBuilder.query(mDb,
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projection,
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selection,
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selectionArgs,
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groupBy,
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having,
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sortOrder);
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c.setNotificationUri(getContext().getContentResolver(), uri);
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return c;</pre>
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*
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* @param uri The URI to query. This will be the full URI sent by the client;
|
|
* if the client is requesting a specific record, the URI will end in a record number
|
|
* that the implementation should parse and add to a WHERE or HAVING clause, specifying
|
|
* that _id value.
|
|
* @param projection The list of columns to put into the cursor. If
|
|
* null all columns are included.
|
|
* @param selection A selection criteria to apply when filtering rows.
|
|
* If null then all rows are included.
|
|
* @param selectionArgs You may include ?s in selection, which will be replaced by
|
|
* the values from selectionArgs, in order that they appear in the selection.
|
|
* The values will be bound as Strings.
|
|
* @param sortOrder How the rows in the cursor should be sorted.
|
|
* If null then the provider is free to define the sort order.
|
|
* @return a Cursor or null.
|
|
*/
|
|
public abstract Cursor query(Uri uri, String[] projection,
|
|
String selection, String[] selectionArgs, String sortOrder);
|
|
|
|
/**
|
|
* Implement this to handle requests for the MIME type of the data at the
|
|
* given URI. The returned MIME type should start with
|
|
* <code>vnd.android.cursor.item</code> for a single record,
|
|
* or <code>vnd.android.cursor.dir/</code> for multiple items.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* <p>Note that there are no permissions needed for an application to
|
|
* access this information; if your content provider requires read and/or
|
|
* write permissions, or is not exported, all applications can still call
|
|
* this method regardless of their access permissions. This allows them
|
|
* to retrieve the MIME type for a URI when dispatching intents.
|
|
*
|
|
* @param uri the URI to query.
|
|
* @return a MIME type string, or null if there is no type.
|
|
*/
|
|
public abstract String getType(Uri uri);
|
|
|
|
/**
|
|
* Implement this to handle requests to insert a new row.
|
|
* As a courtesy, call {@link ContentResolver#notifyChange(android.net.Uri ,android.database.ContentObserver) notifyChange()}
|
|
* after inserting.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
* @param uri The content:// URI of the insertion request.
|
|
* @param values A set of column_name/value pairs to add to the database.
|
|
* @return The URI for the newly inserted item.
|
|
*/
|
|
public abstract Uri insert(Uri uri, ContentValues values);
|
|
|
|
/**
|
|
* Override this to handle requests to insert a set of new rows, or the
|
|
* default implementation will iterate over the values and call
|
|
* {@link #insert} on each of them.
|
|
* As a courtesy, call {@link ContentResolver#notifyChange(android.net.Uri ,android.database.ContentObserver) notifyChange()}
|
|
* after inserting.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* @param uri The content:// URI of the insertion request.
|
|
* @param values An array of sets of column_name/value pairs to add to the database.
|
|
* @return The number of values that were inserted.
|
|
*/
|
|
public int bulkInsert(Uri uri, ContentValues[] values) {
|
|
int numValues = values.length;
|
|
for (int i = 0; i < numValues; i++) {
|
|
insert(uri, values[i]);
|
|
}
|
|
return numValues;
|
|
}
|
|
|
|
/**
|
|
* Implement this to handle requests to delete one or more rows.
|
|
* The implementation should apply the selection clause when performing
|
|
* deletion, allowing the operation to affect multiple rows in a directory.
|
|
* As a courtesy, call {@link ContentResolver#notifyChange(android.net.Uri ,android.database.ContentObserver) notifyDelete()}
|
|
* after deleting.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* <p>The implementation is responsible for parsing out a row ID at the end
|
|
* of the URI, if a specific row is being deleted. That is, the client would
|
|
* pass in <code>content://contacts/people/22</code> and the implementation is
|
|
* responsible for parsing the record number (22) when creating a SQL statement.
|
|
*
|
|
* @param uri The full URI to query, including a row ID (if a specific record is requested).
|
|
* @param selection An optional restriction to apply to rows when deleting.
|
|
* @return The number of rows affected.
|
|
* @throws SQLException
|
|
*/
|
|
public abstract int delete(Uri uri, String selection, String[] selectionArgs);
|
|
|
|
/**
|
|
* Implement this to handle requests to update one or more rows.
|
|
* The implementation should update all rows matching the selection
|
|
* to set the columns according to the provided values map.
|
|
* As a courtesy, call {@link ContentResolver#notifyChange(android.net.Uri ,android.database.ContentObserver) notifyChange()}
|
|
* after updating.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* @param uri The URI to query. This can potentially have a record ID if this
|
|
* is an update request for a specific record.
|
|
* @param values A Bundle mapping from column names to new column values (NULL is a
|
|
* valid value).
|
|
* @param selection An optional filter to match rows to update.
|
|
* @return the number of rows affected.
|
|
*/
|
|
public abstract int update(Uri uri, ContentValues values, String selection,
|
|
String[] selectionArgs);
|
|
|
|
/**
|
|
* Override this to handle requests to open a file blob.
|
|
* The default implementation always throws {@link FileNotFoundException}.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* <p>This method returns a ParcelFileDescriptor, which is returned directly
|
|
* to the caller. This way large data (such as images and documents) can be
|
|
* returned without copying the content.
|
|
*
|
|
* <p>The returned ParcelFileDescriptor is owned by the caller, so it is
|
|
* their responsibility to close it when done. That is, the implementation
|
|
* of this method should create a new ParcelFileDescriptor for each call.
|
|
*
|
|
* @param uri The URI whose file is to be opened.
|
|
* @param mode Access mode for the file. May be "r" for read-only access,
|
|
* "rw" for read and write access, or "rwt" for read and write access
|
|
* that truncates any existing file.
|
|
*
|
|
* @return Returns a new ParcelFileDescriptor which you can use to access
|
|
* the file.
|
|
*
|
|
* @throws FileNotFoundException Throws FileNotFoundException if there is
|
|
* no file associated with the given URI or the mode is invalid.
|
|
* @throws SecurityException Throws SecurityException if the caller does
|
|
* not have permission to access the file.
|
|
*
|
|
* @see #openAssetFile(Uri, String)
|
|
* @see #openFileHelper(Uri, String)
|
|
*/
|
|
public ParcelFileDescriptor openFile(Uri uri, String mode)
|
|
throws FileNotFoundException {
|
|
throw new FileNotFoundException("No files supported by provider at "
|
|
+ uri);
|
|
}
|
|
|
|
/**
|
|
* This is like {@link #openFile}, but can be implemented by providers
|
|
* that need to be able to return sub-sections of files, often assets
|
|
* inside of their .apk.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* <p>If you implement this, your clients must be able to deal with such
|
|
* file slices, either directly with
|
|
* {@link ContentResolver#openAssetFileDescriptor}, or by using the higher-level
|
|
* {@link ContentResolver#openInputStream ContentResolver.openInputStream}
|
|
* or {@link ContentResolver#openOutputStream ContentResolver.openOutputStream}
|
|
* methods.
|
|
*
|
|
* <p class="note">If you are implementing this to return a full file, you
|
|
* should create the AssetFileDescriptor with
|
|
* {@link AssetFileDescriptor#UNKNOWN_LENGTH} to be compatible with
|
|
* applications that can not handle sub-sections of files.</p>
|
|
*
|
|
* @param uri The URI whose file is to be opened.
|
|
* @param mode Access mode for the file. May be "r" for read-only access,
|
|
* "w" for write-only access (erasing whatever data is currently in
|
|
* the file), "wa" for write-only access to append to any existing data,
|
|
* "rw" for read and write access on any existing data, and "rwt" for read
|
|
* and write access that truncates any existing file.
|
|
*
|
|
* @return Returns a new AssetFileDescriptor which you can use to access
|
|
* the file.
|
|
*
|
|
* @throws FileNotFoundException Throws FileNotFoundException if there is
|
|
* no file associated with the given URI or the mode is invalid.
|
|
* @throws SecurityException Throws SecurityException if the caller does
|
|
* not have permission to access the file.
|
|
*
|
|
* @see #openFile(Uri, String)
|
|
* @see #openFileHelper(Uri, String)
|
|
*/
|
|
public AssetFileDescriptor openAssetFile(Uri uri, String mode)
|
|
throws FileNotFoundException {
|
|
ParcelFileDescriptor fd = openFile(uri, mode);
|
|
return fd != null ? new AssetFileDescriptor(fd, 0, -1) : null;
|
|
}
|
|
|
|
/**
|
|
* Convenience for subclasses that wish to implement {@link #openFile}
|
|
* by looking up a column named "_data" at the given URI.
|
|
*
|
|
* @param uri The URI to be opened.
|
|
* @param mode The file mode. May be "r" for read-only access,
|
|
* "w" for write-only access (erasing whatever data is currently in
|
|
* the file), "wa" for write-only access to append to any existing data,
|
|
* "rw" for read and write access on any existing data, and "rwt" for read
|
|
* and write access that truncates any existing file.
|
|
*
|
|
* @return Returns a new ParcelFileDescriptor that can be used by the
|
|
* client to access the file.
|
|
*/
|
|
protected final ParcelFileDescriptor openFileHelper(Uri uri,
|
|
String mode) throws FileNotFoundException {
|
|
Cursor c = query(uri, new String[]{"_data"}, null, null, null);
|
|
int count = (c != null) ? c.getCount() : 0;
|
|
if (count != 1) {
|
|
// If there is not exactly one result, throw an appropriate
|
|
// exception.
|
|
if (c != null) {
|
|
c.close();
|
|
}
|
|
if (count == 0) {
|
|
throw new FileNotFoundException("No entry for " + uri);
|
|
}
|
|
throw new FileNotFoundException("Multiple items at " + uri);
|
|
}
|
|
|
|
c.moveToFirst();
|
|
int i = c.getColumnIndex("_data");
|
|
String path = (i >= 0 ? c.getString(i) : null);
|
|
c.close();
|
|
if (path == null) {
|
|
throw new FileNotFoundException("Column _data not found.");
|
|
}
|
|
|
|
int modeBits = ContentResolver.modeToMode(uri, mode);
|
|
return ParcelFileDescriptor.open(new File(path), modeBits);
|
|
}
|
|
|
|
/**
|
|
* Returns true if this instance is a temporary content provider.
|
|
* @return true if this instance is a temporary content provider
|
|
*/
|
|
protected boolean isTemporary() {
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Returns the Binder object for this provider.
|
|
*
|
|
* @return the Binder object for this provider
|
|
* @hide
|
|
*/
|
|
public IContentProvider getIContentProvider() {
|
|
return mTransport;
|
|
}
|
|
|
|
/**
|
|
* After being instantiated, this is called to tell the content provider
|
|
* about itself.
|
|
*
|
|
* @param context The context this provider is running in
|
|
* @param info Registered information about this content provider
|
|
*/
|
|
public void attachInfo(Context context, ProviderInfo info) {
|
|
|
|
/*
|
|
* Only allow it to be set once, so after the content service gives
|
|
* this to us clients can't change it.
|
|
*/
|
|
if (mContext == null) {
|
|
mContext = context;
|
|
mMyUid = Process.myUid();
|
|
if (info != null) {
|
|
setReadPermission(info.readPermission);
|
|
setWritePermission(info.writePermission);
|
|
setPathPermissions(info.pathPermissions);
|
|
mExported = info.exported;
|
|
}
|
|
ContentProvider.this.onCreate();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Override this to handle requests to perform a batch of operations, or the
|
|
* default implementation will iterate over the operations and call
|
|
* {@link ContentProviderOperation#apply} on each of them.
|
|
* If all calls to {@link ContentProviderOperation#apply} succeed
|
|
* then a {@link ContentProviderResult} array with as many
|
|
* elements as there were operations will be returned. If any of the calls
|
|
* fail, it is up to the implementation how many of the others take effect.
|
|
* This method can be called from multiple threads, as described in
|
|
* <a href="{@docRoot}guide/topics/fundamentals.html#procthread">Application Fundamentals:
|
|
* Processes and Threads</a>.
|
|
*
|
|
* @param operations the operations to apply
|
|
* @return the results of the applications
|
|
* @throws OperationApplicationException thrown if any operation fails.
|
|
* @see ContentProviderOperation#apply
|
|
*/
|
|
public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
|
|
throws OperationApplicationException {
|
|
final int numOperations = operations.size();
|
|
final ContentProviderResult[] results = new ContentProviderResult[numOperations];
|
|
for (int i = 0; i < numOperations; i++) {
|
|
results[i] = operations.get(i).apply(this, results, i);
|
|
}
|
|
return results;
|
|
}
|
|
|
|
/**
|
|
* @hide -- until interface has proven itself
|
|
*
|
|
* Call an provider-defined method. This can be used to implement
|
|
* interfaces that are cheaper than using a Cursor.
|
|
*
|
|
* @param method Method name to call. Opaque to framework.
|
|
* @param request Nullable String argument passed to method.
|
|
* @param args Nullable Bundle argument passed to method.
|
|
*/
|
|
public Bundle call(String method, String request, Bundle args) {
|
|
return null;
|
|
}
|
|
}
|