M7350/base/core/java/android/content/ContentProvider.java
2024-09-09 08:52:07 +00:00

843 lines
35 KiB
Java

/*
* Copyright (C) 2006 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.content;
import android.content.pm.PackageManager;
import android.content.pm.PathPermission;
import android.content.pm.ProviderInfo;
import android.content.res.AssetFileDescriptor;
import android.content.res.Configuration;
import android.database.Cursor;
import android.database.CursorToBulkCursorAdaptor;
import android.database.CursorWindow;
import android.database.IBulkCursor;
import android.database.IContentObserver;
import android.database.SQLException;
import android.net.Uri;
import android.os.Binder;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
/**
* Content providers are one of the primary building blocks of Android applications, providing
* content to applications. They encapsulate data and provide it to applications through the single
* {@link ContentResolver} interface. A content provider is only required if you need to share
* data between multiple applications. For example, the contacts data is used by multiple
* applications and must be stored in a content provider. If you don't need to share data amongst
* multiple applications you can use a database directly via
* {@link android.database.sqlite.SQLiteDatabase}.
*
* <p>For more information, read <a href="{@docRoot}guide/topics/providers/content-providers.html">Content
* Providers</a>.</p>
*
* <p>When a request is made via
* a {@link ContentResolver} the system inspects the authority of the given URI and passes the
* request to the content provider registered with the authority. The content provider can interpret
* the rest of the URI however it wants. The {@link UriMatcher} class is helpful for parsing
* URIs.</p>
*
* <p>The primary methods that need to be implemented are:
* <ul>
* <li>{@link #onCreate} which is called to initialize the provider</li>
* <li>{@link #query} which returns data to the caller</li>
* <li>{@link #insert} which inserts new data into the content provider</li>
* <li>{@link #update} which updates existing data in the content provider</li>
* <li>{@link #delete} which deletes data from the content provider</li>
* <li>{@link #getType} which returns the MIME type of data in the content provider</li>
* </ul></p>
*
* <p class="caution">Data access methods (such as {@link #insert} and
* {@link #update}) may be called from many threads at once, and must be thread-safe.
* Other methods (such as {@link #onCreate}) are only called from the application
* main thread, and must avoid performing lengthy operations. See the method
* descriptions for their expected thread behavior.</p>
*
* <p>Requests to {@link ContentResolver} are automatically forwarded to the appropriate
* ContentProvider instance, so subclasses don't have to worry about the details of
* cross-process calls.</p>
*/
public abstract class ContentProvider implements ComponentCallbacks {
/*
* Note: if you add methods to ContentProvider, you must add similar methods to
* MockContentProvider.
*/
private Context mContext = null;
private int mMyUid;
private String mReadPermission;
private String mWritePermission;
private PathPermission[] mPathPermissions;
private boolean mExported;
private Transport mTransport = new Transport();
/**
* Construct a ContentProvider instance. Content providers must be
* <a href="{@docRoot}guide/topics/manifest/provider-element.html">declared
* in the manifest</a>, accessed with {@link ContentResolver}, and created
* automatically by the system, so applications usually do not create
* ContentProvider instances directly.
*
* <p>At construction time, the object is uninitialized, and most fields and
* methods are unavailable. Subclasses should initialize themselves in
* {@link #onCreate}, not the constructor.
*
* <p>Content providers are created on the application main thread at
* application launch time. The constructor must not perform lengthy
* operations, or application startup will be delayed.
*/
public ContentProvider() {
}
/**
* Constructor just for mocking.
*
* @param context A Context object which should be some mock instance (like the
* instance of {@link android.test.mock.MockContext}).
* @param readPermission The read permision you want this instance should have in the
* test, which is available via {@link #getReadPermission()}.
* @param writePermission The write permission you want this instance should have
* in the test, which is available via {@link #getWritePermission()}.
* @param pathPermissions The PathPermissions you want this instance should have
* in the test, which is available via {@link #getPathPermissions()}.
* @hide
*/
public ContentProvider(
Context context,
String readPermission,
String writePermission,
PathPermission[] pathPermissions) {
mContext = context;
mReadPermission = readPermission;
mWritePermission = writePermission;
mPathPermissions = pathPermissions;
}
/**
* Given an IContentProvider, try to coerce it back to the real
* ContentProvider object if it is running in the local process. This can
* be used if you know you are running in the same process as a provider,
* and want to get direct access to its implementation details. Most
* clients should not nor have a reason to use it.
*
* @param abstractInterface The ContentProvider interface that is to be
* coerced.
* @return If the IContentProvider is non-null and local, returns its actual
* ContentProvider instance. Otherwise returns null.
* @hide
*/
public static ContentProvider coerceToLocalContentProvider(
IContentProvider abstractInterface) {
if (abstractInterface instanceof Transport) {
return ((Transport)abstractInterface).getContentProvider();
}
return null;
}
/**
* Binder object that deals with remoting.
*
* @hide
*/
class Transport extends ContentProviderNative {
ContentProvider getContentProvider() {
return ContentProvider.this;
}
/**
* Remote version of a query, which returns an IBulkCursor. The bulk
* cursor should be wrapped with BulkCursorToCursorAdaptor before use.
*/
public IBulkCursor bulkQuery(Uri uri, String[] projection,
String selection, String[] selectionArgs, String sortOrder,
IContentObserver observer, CursorWindow window) {
enforceReadPermission(uri);
Cursor cursor = ContentProvider.this.query(uri, projection,
selection, selectionArgs, sortOrder);
if (cursor == null) {
return null;
}
return new CursorToBulkCursorAdaptor(cursor, observer,
ContentProvider.this.getClass().getName(),
hasWritePermission(uri), window);
}
public Cursor query(Uri uri, String[] projection,
String selection, String[] selectionArgs, String sortOrder) {
enforceReadPermission(uri);
return ContentProvider.this.query(uri, projection, selection,
selectionArgs, sortOrder);
}
public String getType(Uri uri) {
return ContentProvider.this.getType(uri);
}
public Uri insert(Uri uri, ContentValues initialValues) {
enforceWritePermission(uri);
return ContentProvider.this.insert(uri, initialValues);
}
public int bulkInsert(Uri uri, ContentValues[] initialValues) {
enforceWritePermission(uri);
return ContentProvider.this.bulkInsert(uri, initialValues);
}
public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
throws OperationApplicationException {
for (ContentProviderOperation operation : operations) {
if (operation.isReadOperation()) {
enforceReadPermission(operation.getUri());
}
if (operation.isWriteOperation()) {
enforceWritePermission(operation.getUri());
}
}
return ContentProvider.this.applyBatch(operations);
}
public int delete(Uri uri, String selection, String[] selectionArgs) {
enforceWritePermission(uri);
return ContentProvider.this.delete(uri, selection, selectionArgs);
}
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
enforceWritePermission(uri);
return ContentProvider.this.update(uri, values, selection, selectionArgs);
}
public ParcelFileDescriptor openFile(Uri uri, String mode)
throws FileNotFoundException {
if (mode != null && mode.startsWith("rw")) enforceWritePermission(uri);
else enforceReadPermission(uri);
return ContentProvider.this.openFile(uri, mode);
}
public AssetFileDescriptor openAssetFile(Uri uri, String mode)
throws FileNotFoundException {
if (mode != null && mode.startsWith("rw")) enforceWritePermission(uri);
else enforceReadPermission(uri);
return ContentProvider.this.openAssetFile(uri, mode);
}
/**
* @hide
*/
public Bundle call(String method, String request, Bundle args) {
return ContentProvider.this.call(method, request, args);
}
private void enforceReadPermission(Uri uri) {
final int uid = Binder.getCallingUid();
if (uid == mMyUid) {
return;
}
final Context context = getContext();
final String rperm = getReadPermission();
final int pid = Binder.getCallingPid();
if (mExported && (rperm == null
|| context.checkPermission(rperm, pid, uid)
== PackageManager.PERMISSION_GRANTED)) {
return;
}
PathPermission[] pps = getPathPermissions();
if (pps != null) {
final String path = uri.getPath();
int i = pps.length;
while (i > 0) {
i--;
final PathPermission pp = pps[i];
final String pprperm = pp.getReadPermission();
if (pprperm != null && pp.match(path)) {
if (context.checkPermission(pprperm, pid, uid)
== PackageManager.PERMISSION_GRANTED) {
return;
}
}
}
}
if (context.checkUriPermission(uri, pid, uid,
Intent.FLAG_GRANT_READ_URI_PERMISSION)
== PackageManager.PERMISSION_GRANTED) {
return;
}
String msg = "Permission Denial: reading "
+ ContentProvider.this.getClass().getName()
+ " uri " + uri + " from pid=" + Binder.getCallingPid()
+ ", uid=" + Binder.getCallingUid()
+ " requires " + rperm;
throw new SecurityException(msg);
}
private boolean hasWritePermission(Uri uri) {
final int uid = Binder.getCallingUid();
if (uid == mMyUid) {
return true;
}
final Context context = getContext();
final String wperm = getWritePermission();
final int pid = Binder.getCallingPid();
if (mExported && (wperm == null
|| context.checkPermission(wperm, pid, uid)
== PackageManager.PERMISSION_GRANTED)) {
return true;
}
PathPermission[] pps = getPathPermissions();
if (pps != null) {
final String path = uri.getPath();
int i = pps.length;
while (i > 0) {
i--;
final PathPermission pp = pps[i];
final String ppwperm = pp.getWritePermission();
if (ppwperm != null && pp.match(path)) {
if (context.checkPermission(ppwperm, pid, uid)
== PackageManager.PERMISSION_GRANTED) {
return true;
}
}
}
}
if (context.checkUriPermission(uri, pid, uid,
Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
== PackageManager.PERMISSION_GRANTED) {
return true;
}
return false;
}
private void enforceWritePermission(Uri uri) {
if (hasWritePermission(uri)) {
return;
}
String msg = "Permission Denial: writing "
+ ContentProvider.this.getClass().getName()
+ " uri " + uri + " from pid=" + Binder.getCallingPid()
+ ", uid=" + Binder.getCallingUid()
+ " requires " + getWritePermission();
throw new SecurityException(msg);
}
}
/**
* Retrieves the Context this provider is running in. Only available once
* {@link #onCreate} has been called -- this will return null in the
* constructor.
*/
public final Context getContext() {
return mContext;
}
/**
* Change the permission required to read data from the content
* provider. This is normally set for you from its manifest information
* when the provider is first created.
*
* @param permission Name of the permission required for read-only access.
*/
protected final void setReadPermission(String permission) {
mReadPermission = permission;
}
/**
* Return the name of the permission required for read-only access to
* this content provider. 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>.
*/
public final String getReadPermission() {
return mReadPermission;
}
/**
* Change the permission required to read and write data in the content
* provider. This is normally set for you from its manifest information
* when the provider is first created.
*
* @param permission Name of the permission required for read/write access.
*/
protected final void setWritePermission(String permission) {
mWritePermission = permission;
}
/**
* Return the name of the permission required for read/write access to
* this content provider. 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>.
*/
public final String getWritePermission() {
return mWritePermission;
}
/**
* Change the path-based permission required to read and/or write data in
* the content provider. This is normally set for you from its manifest
* information when the provider is first created.
*
* @param permissions Array of path permission descriptions.
*/
protected final void setPathPermissions(PathPermission[] permissions) {
mPathPermissions = permissions;
}
/**
* Return the path-based permissions required for read and/or write access to
* this content provider. 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>.
*/
public final PathPermission[] getPathPermissions() {
return mPathPermissions;
}
/**
* Implement this to initialize your content provider on startup.
* This method is called for all registered content providers on the
* application main thread at application launch time. It must not perform
* lengthy operations, or application startup will be delayed.
*
* <p>You should defer nontrivial initialization (such as opening,
* upgrading, and scanning databases) until the content provider is used
* (via {@link #query}, {@link #insert}, etc). Deferred initialization
* keeps application startup fast, avoids unnecessary work if the provider
* turns out not to be needed, and stops database errors (such as a full
* disk) from halting application launch.
*
* <p>If you use SQLite, {@link android.database.sqlite.SQLiteOpenHelper}
* is a helpful utility class that makes it easy to manage databases,
* and will automatically defer opening until first use. If you do use
* SQLiteOpenHelper, make sure to avoid calling
* {@link android.database.sqlite.SQLiteOpenHelper#getReadableDatabase} or
* {@link android.database.sqlite.SQLiteOpenHelper#getWritableDatabase}
* from this method. (Instead, override
* {@link android.database.sqlite.SQLiteOpenHelper#onOpen} to initialize the
* database when it is first opened.)
*
* @return true if the provider was successfully loaded, false otherwise
*/
public abstract boolean onCreate();
/**
* {@inheritDoc}
* This method is always called on the application main thread, and must
* not perform lengthy operations.
*
* <p>The default content provider implementation does nothing.
* Override this method to take appropriate action.
* (Content providers do not usually care about things like screen
* orientation, but may want to know about locale changes.)
*/
public void onConfigurationChanged(Configuration newConfig) {
}
/**
* {@inheritDoc}
* This method is always called on the application main thread, and must
* not perform lengthy operations.
*
* <p>The default content provider implementation does nothing.
* Subclasses may override this method to take appropriate action.
*/
public void onLowMemory() {
}
/**
* Implement this to handle query requests from clients.
* 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>
* Example client call:<p>
* <pre>// Request a specific record.
* Cursor managedCursor = managedQuery(
ContentUris.withAppendedId(Contacts.People.CONTENT_URI, 2),
projection, // Which columns to return.
null, // WHERE clause.
null, // WHERE clause value substitution
People.NAME + " ASC"); // Sort order.</pre>
* Example implementation:<p>
* <pre>// SQLiteQueryBuilder is a helper class that creates the
// proper SQL syntax for us.
SQLiteQueryBuilder qBuilder = new SQLiteQueryBuilder();
// Set the table we're querying.
qBuilder.setTables(DATABASE_TABLE_NAME);
// If the query ends in a specific record number, we're
// being asked for a specific record, so set the
// WHERE clause in our query.
if((URI_MATCHER.match(uri)) == SPECIFIC_MESSAGE){
qBuilder.appendWhere("_id=" + uri.getPathLeafId());
}
// Make the query.
Cursor c = qBuilder.query(mDb,
projection,
selection,
selectionArgs,
groupBy,
having,
sortOrder);
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;</pre>
*
* @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;
}
}