ContentProvider
abstract class ContentProvider : ComponentCallbacks2
kotlin.Any | |
↳ | android.content.ContentProvider |
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 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 android.database.sqlite.SQLiteDatabase
.
When a request is made via a 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 UriMatcher
class is helpful for parsing URIs.
The primary methods that need to be implemented are:
onCreate
which is called to initialize the provider- query which returns data to the caller
- insert which inserts new data into the content provider
- update which updates existing data in the content provider
- delete which deletes data from the content provider
getType
which returns the MIME type of data in the content provider
Data access methods (such as #insert and #update) may be called from many threads at once, and must be thread-safe. Other methods (such as onCreate
) are only called from the application main thread, and must avoid performing lengthy operations. See the method descriptions for their expected thread behavior.
Requests to ContentResolver
are automatically forwarded to the appropriate ContentProvider instance, so subclasses don't have to worry about the details of cross-process calls.
Summary
Nested classes | |
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Opaque token representing the identity of an incoming IPC. |
|
abstract |
Interface to write a stream of data to a pipe. |
Inherited constants | |
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Public constructors | |
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Construct a ContentProvider instance. |
Public methods | |
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open Array<ContentProviderResult!> |
applyBatch(authority: String, operations: ArrayList<ContentProviderOperation!>) Override this to handle requests to perform a batch of operations, or the default implementation will iterate over the operations and call |
open Array<ContentProviderResult!> |
applyBatch(operations: ArrayList<ContentProviderOperation!>) |
open Unit |
attachInfo(context: Context!, info: ProviderInfo!) After being instantiated, this is called to tell the content provider about itself. |
open Int |
bulkInsert(uri: Uri, values: Array<ContentValues!>) Override this to handle requests to insert a set of new rows, or the default implementation will iterate over the values and call #insert on each of them. |
open Bundle? |
Call a provider-defined method. |
open Bundle? | |
open Uri? |
canonicalize(url: Uri) Implement this to support canonicalization of URIs that refer to your content provider. |
ContentProvider.CallingIdentity |
Reset the identity of the incoming IPC on the current thread. |
abstract Int |
Implement this to handle requests to delete one or more rows. |
open Int |
Implement this to handle requests to delete one or more rows. |
open Unit |
dump(fd: FileDescriptor!, writer: PrintWriter!, args: Array<String!>!) Print the Provider's state into the given stream. |
AttributionSource? |
Gets the attribution source of the calling app. |
String? |
Return the attribution tag of the caller that initiated the request being processed on the current thread. |
String? |
Return the package name of the caller that initiated the request being processed on the current thread. |
String? |
Return the package name of the caller that initiated the request being processed on the current thread. |
Context? |
Retrieves the Context this provider is running in. |
Array<PathPermission!>? |
Return the path-based permissions required for read and/or write access to this content provider. |
String? |
Return the name of the permission required for read-only access to this content provider. |
open Array<String!>? |
getStreamTypes(uri: Uri, mimeTypeFilter: String) Called by a client to determine the types of data streams that this content provider supports for the given URI. |
abstract String? |
Implement this to handle requests for the MIME type of the data at the given URI. |
open String? |
getTypeAnonymous(uri: Uri) Implement this to handle requests for MIME type of URIs, that does not need to reveal any internal information which should be protected by any permission. |
String? |
Return the name of the permission required for read/write access to this content provider. |
abstract Uri? |
insert(uri: Uri, values: ContentValues?) Implement this to handle requests to insert a new row. |
open Uri? |
insert(uri: Uri, values: ContentValues?, extras: Bundle?) Implement this to handle requests to insert a new row. |
open Unit |
Called whenever the value of |
open Unit |
onConfigurationChanged(newConfig: Configuration) Called by the system when the device configuration changes while your component is running. |
abstract Boolean |
onCreate() Implement this to initialize your content provider on startup. |
open Unit |
This is called when the overall system is running low on memory, and actively running processes should trim their memory usage. |
open Unit |
onTrimMemory(level: Int) |
open AssetFileDescriptor? |
openAssetFile(uri: Uri, mode: String) This is like #openFile, but can be implemented by providers that need to be able to return sub-sections of files, often assets inside of their . |
open AssetFileDescriptor? |
openAssetFile(uri: Uri, mode: String, signal: CancellationSignal?) This is like #openFile, but can be implemented by providers that need to be able to return sub-sections of files, often assets inside of their . |
open ParcelFileDescriptor? |
Override this to handle requests to open a file blob. |
open ParcelFileDescriptor? |
openFile(uri: Uri, mode: String, signal: CancellationSignal?) Override this to handle requests to open a file blob. |
open ParcelFileDescriptor |
openPipeHelper(uri: Uri, mimeType: String, opts: Bundle?, args: T?, func: ContentProvider.PipeDataWriter<T>) A helper function for implementing #openTypedAssetFile, for creating a data pipe and background thread allowing you to stream generated data back to the client. |
open AssetFileDescriptor? |
openTypedAssetFile(uri: Uri, mimeTypeFilter: String, opts: Bundle?) Called by a client to open a read-only stream containing data of a particular MIME type. |
open AssetFileDescriptor? |
openTypedAssetFile(uri: Uri, mimeTypeFilter: String, opts: Bundle?, signal: CancellationSignal?) Called by a client to open a read-only stream containing data of a particular MIME type. |
abstract Cursor? |
query(uri: Uri, projection: Array<String!>?, selection: String?, selectionArgs: Array<String!>?, sortOrder: String?) Implement this to handle query requests from clients. |
open Cursor? |
query(uri: Uri, projection: Array<String!>?, selection: String?, selectionArgs: Array<String!>?, sortOrder: String?, cancellationSignal: CancellationSignal?) Implement this to handle query requests from clients with support for cancellation. |
open Cursor? |
query(uri: Uri, projection: Array<String!>?, queryArgs: Bundle?, cancellationSignal: CancellationSignal?) Implement this to handle query requests where the arguments are packed into a |
open Boolean |
refresh(uri: Uri!, extras: Bundle?, cancellationSignal: CancellationSignal?) Implement this to support refresh of content identified by |
Context |
Retrieves a Non-Nullable Context this provider is running in, this is intended to be called after |
Unit |
Restore the identity of the incoming IPC on the current thread back to a previously identity that was returned by |
open Unit |
shutdown() Implement this to shut down the ContentProvider instance. |
open Uri? |
uncanonicalize(url: Uri) Remove canonicalization from canonical URIs previously returned by |
abstract Int |
Implement this to handle requests to update one or more rows. |
open Int |
update(uri: Uri, values: ContentValues?, extras: Bundle?) Implement this to handle requests to update one or more rows. |
Protected methods | |
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open Boolean |
Returns true if this instance is a temporary content provider. |
ParcelFileDescriptor |
openFileHelper(uri: Uri, mode: String) Convenience for subclasses that wish to implement #openFile by looking up a column named "_data" at the given URI. |
Unit |
setPathPermissions(permissions: Array<PathPermission!>?) Change the path-based permission required to read and/or write data in the content provider. |
Unit |
setReadPermission(permission: String?) Change the permission required to read data from the content provider. |
Unit |
setWritePermission(permission: String?) Change the permission required to read and write data in the content provider. |
Inherited functions | |
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Public constructors
ContentProvider
ContentProvider()
Construct a ContentProvider instance. Content providers must be declared in the manifest, accessed with ContentResolver
, and created automatically by the system, so applications usually do not create ContentProvider instances directly.
At construction time, the object is uninitialized, and most fields and methods are unavailable. Subclasses should initialize themselves in onCreate
, not the constructor.
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 methods
applyBatch
open fun applyBatch(
authority: String,
operations: ArrayList<ContentProviderOperation!>
): Array<ContentProviderResult!>
Override this to handle requests to perform a batch of operations, or the default implementation will iterate over the operations and call ContentProviderOperation#apply
on each of them. If all calls to ContentProviderOperation#apply
succeed then a 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 Processes and Threads.
Parameters | |
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operations |
ArrayList<ContentProviderOperation!>: the operations to apply This value cannot be null . |
authority |
String: This value cannot be null . |
Return | |
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Array<ContentProviderResult!> |
the results of the applications This value cannot be null . |
Exceptions | |
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android.content.OperationApplicationException |
thrown if any operation fails. |
applyBatch
open fun applyBatch(operations: ArrayList<ContentProviderOperation!>): Array<ContentProviderResult!>
Parameters | |
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operations |
ArrayList<ContentProviderOperation!>: This value cannot be null . |
Return | |
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Array<ContentProviderResult!> |
This value cannot be null . |
attachInfo
open fun attachInfo(
context: Context!,
info: ProviderInfo!
): Unit
After being instantiated, this is called to tell the content provider about itself.
Parameters | |
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context |
Context!: The context this provider is running in |
info |
ProviderInfo!: Registered information about this content provider |
bulkInsert
open fun bulkInsert(
uri: Uri,
values: Array<ContentValues!>
): Int
Override this to handle requests to insert a set of new rows, or the default implementation will iterate over the values and call #insert on each of them. As a courtesy, call notifyChange()
after inserting. This method can be called from multiple threads, as described in Processes and Threads.
Parameters | |
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uri |
Uri: The content:// URI of the insertion request. This value cannot be null . |
values |
Array<ContentValues!>: An array of sets of column_name/value pairs to add to the database. This must not be null . |
Return | |
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Int |
The number of values that were inserted. |
call
open fun call(
authority: String,
method: String,
arg: String?,
extras: Bundle?
): Bundle?
Call a provider-defined method. This can be used to implement interfaces that are cheaper and/or unnatural for a table-like model.
WARNING: The framework does no permission checking on this entry into the content provider besides the basic ability for the application to get access to the provider at all. For example, it has no idea whether the call being executed may read or write data in the provider, so can't enforce those individual permissions. Any implementation of this method must do its own permission checks on incoming calls to make sure they are allowed.
Parameters | |
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method |
String: method name to call. Opaque to framework, but should not be null . |
arg |
String?: provider-defined String argument. May be null . |
extras |
Bundle?: provider-defined Bundle argument. May be null . |
authority |
String: This value cannot be null . |
Return | |
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Bundle? |
provider-defined return value. May be null , which is also the default for providers which don't implement any call methods. |
call
open fun call(
method: String,
arg: String?,
extras: Bundle?
): Bundle?
Parameters | |
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method |
String: This value cannot be null . |
arg |
String?: This value may be null . |
extras |
Bundle?: This value may be null . |
Return | |
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Bundle? |
This value may be null . |
canonicalize
open fun canonicalize(url: Uri): Uri?
Implement this to support canonicalization of URIs that refer to your content provider. A canonical URI is one that can be transported across devices, backup/restore, and other contexts, and still be able to refer to the same data item. Typically this is implemented by adding query params to the URI allowing the content provider to verify that an incoming canonical URI references the same data as it was originally intended for and, if it doesn't, to find that data (if it exists) in the current environment.
For example, if the content provider holds people and a normal URI in it is created with a row index into that people database, the cananical representation may have an additional query param at the end which specifies the name of the person it is intended for. Later calls into the provider with that URI will look up the row of that URI's base index and, if it doesn't match or its entry's name doesn't match the name in the query param, perform a query on its database to find the correct row to operate on.
If you implement support for canonical URIs, all incoming calls with URIs (including this one) must perform this verification and recovery of any canonical URIs they receive. In addition, you must also implement uncanonicalize
to strip the canonicalization of any of these URIs.
The default implementation of this method returns null, indicating that canonical URIs are not supported.
Parameters | |
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url |
Uri: The Uri to canonicalize. This value cannot be null . |
Return | |
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Uri? |
Return the canonical representation of url, or null if canonicalization of that Uri is not supported. |
clearCallingIdentity
fun clearCallingIdentity(): ContentProvider.CallingIdentity
Reset the identity of the incoming IPC on the current thread.
Internally this calls Binder#clearCallingIdentity()
and also clears any value stored in getCallingPackage()
.
Return | |
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ContentProvider.CallingIdentity |
Returns an opaque token that can be used to restore the original calling identity by passing it to restoreCallingIdentity . This value cannot be null . |
delete
abstract fun delete(
uri: Uri,
selection: String?,
selectionArgs: Array<String!>?
): Int
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 notifyChange()
after deleting. This method can be called from multiple threads, as described in Processes and Threads.
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 content://contacts/people/22
and the implementation is responsible for parsing the record number (22) when creating a SQL statement.
Parameters | |
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uri |
Uri: The full URI to query, including a row ID (if a specific record is requested). This value cannot be null . |
selection |
String?: An optional restriction to apply to rows when deleting. This value may be null . |
selectionArgs |
Array<String!>?: This value may be null . |
Return | |
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Int |
The number of rows affected. |
Exceptions | |
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android.database.SQLException |
delete
open fun delete(
uri: Uri,
extras: Bundle?
): Int
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 notifyChange()
after deleting. This method can be called from multiple threads, as described in Processes and Threads.
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 content://contacts/people/22
and the implementation is responsible for parsing the record number (22) when creating a SQL statement.
Parameters | |
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uri |
Uri: The full URI to query, including a row ID (if a specific record is requested). This value cannot be null . |
extras |
Bundle?: A Bundle containing additional information necessary for the operation. Arguments may include SQL style arguments, such as ContentResolver#QUERY_ARG_SQL_LIMIT , but note that the documentation for each individual provider will indicate which arguments they support. This value may be null . |
Exceptions | |
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java.lang.IllegalArgumentException |
if the provider doesn't support one of the requested Bundle arguments. |
android.database.SQLException |
dump
open fun dump(
fd: FileDescriptor!,
writer: PrintWriter!,
args: Array<String!>!
): Unit
Print the Provider's state into the given stream. This gets invoked if you run "adb shell dumpsys activity provider <provider_component_name>".
Parameters | |
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fd |
FileDescriptor!: The raw file descriptor that the dump is being sent to. |
writer |
PrintWriter!: The PrintWriter to which you should dump your state. This will be closed for you after you return. |
args |
Array<String!>!: additional arguments to the dump request. |
getCallingAttributionSource
fun getCallingAttributionSource(): AttributionSource?
Gets the attribution source of the calling app. If you want to attribute the data access to the calling app you can create an attribution context via android.content.Context#createContext(ContextParams)
and passing this identity to ContextParams.Builder#setNextAttributionSource(
.
Return | |
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AttributionSource? |
The identity of the caller for permission purposes. This value may be null . |
getCallingAttributionTag
fun getCallingAttributionTag(): String?
Return the attribution tag of the caller that initiated the request being processed on the current thread. Returns null
if not currently processing a request of the request is for the default attribution.
This will always return null
when processing getTypeAnonymous(android.net.Uri)
requests For getType(android.net.Uri)
requests, this will be only available for cases, where the caller can be identified. See getTypeAnonymous(android.net.Uri)
See Also
getCallingPackage
fun getCallingPackage(): String?
Return the package name of the caller that initiated the request being processed on the current thread. The returned package will have been verified to belong to the calling UID. Returns null
if not currently processing a request.
This will always return null
when processing getTypeAnonymous(android.net.Uri)
requests For getType(android.net.Uri)
requests, this will be only available for cases, where the caller can be identified. See getTypeAnonymous(android.net.Uri)
Exceptions | |
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java.lang.SecurityException |
if the calling package doesn't belong to the calling UID. |
getCallingPackageUnchecked
fun getCallingPackageUnchecked(): String?
Return the package name of the caller that initiated the request being processed on the current thread. The returned package will have not been verified to belong to the calling UID. Returns null
if not currently processing a request.
This will always return null
when processing getTypeAnonymous(android.net.Uri)
requests For getType(android.net.Uri)
requests, this will be only available for cases, where the caller can be identified. See getTypeAnonymous(android.net.Uri)
getContext
fun getContext(): Context?
Retrieves the Context this provider is running in. Only available once onCreate
has been called -- this will return null
in the constructor.
getPathPermissions
fun getPathPermissions(): Array<PathPermission!>?
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 Processes and Threads.
Return | |
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Array<PathPermission!>? |
This value may be null . |
getReadPermission
fun getReadPermission(): String?
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 Processes and Threads.
Return | |
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String? |
This value may be null . |
getStreamTypes
open fun getStreamTypes(
uri: Uri,
mimeTypeFilter: String
): Array<String!>?
Called by a client to determine the types of data streams that this content provider supports for the given URI. The default implementation returns null
, meaning no types. If your content provider stores data of a particular type, return that MIME type if it matches the given mimeTypeFilter. If it can perform type conversions, return an array of all supported MIME types that match mimeTypeFilter.
Parameters | |
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uri |
Uri: The data in the content provider being queried. This value cannot be null . |
mimeTypeFilter |
String: The type of data the client desires. May be a pattern, such as */* to retrieve all possible data types. This value cannot be null . |
Return | |
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Array<String!>? |
Returns null if there are no possible data streams for the given mimeTypeFilter. Otherwise returns an array of all available concrete MIME types. |
getType
abstract fun getType(uri: Uri): String?
Implement this to handle requests for the MIME type of the data at the given URI. The returned MIME type should start with vnd.android.cursor.item
for a single record, or vnd.android.cursor.dir/
for multiple items. This method can be called from multiple threads, as described in Processes and Threads.
Note that by default 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.
If your mime type reveals details that should be protected, then you should protect this method by implementing getTypeAnonymous
. Implementing getTypeAnonymous
ensures your getType
can be only accessed by caller's having associated readPermission for the URI.
Parameters | |
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uri |
Uri: the URI to query. This value cannot be null . |
Return | |
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String? |
a MIME type string, or null if there is no type. |
getTypeAnonymous
open fun getTypeAnonymous(uri: Uri): String?
Implement this to handle requests for MIME type of URIs, that does not need to reveal any internal information which should be protected by any permission.
If your mime type reveals details that should be protected, then you should protect those by implementing those in getType
, and in this function, only return types of URIs which can be obtained by anyone without any access. Implementing ths function will make sure getType
is protected by readPermission. This function by default works as the getType
Parameters | |
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uri |
Uri: the URI to query. This value cannot be null . |
Return | |
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String? |
a MIME type string, or null if type needs to be protected. |
getWritePermission
fun getWritePermission(): String?
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 Processes and Threads.
Return | |
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String? |
This value may be null . |
insert
abstract fun insert(
uri: Uri,
values: ContentValues?
): Uri?
Implement this to handle requests to insert a new row. As a courtesy, call notifyChange()
after inserting. This method can be called from multiple threads, as described in Processes and Threads.
Parameters | |
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uri |
Uri: The content:// URI of the insertion request. This value cannot be null . |
values |
ContentValues?: A set of column_name/value pairs to add to the database. This value may be null . |
Return | |
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Uri? |
The URI for the newly inserted item. This value may be null . |
insert
open fun insert(
uri: Uri,
values: ContentValues?,
extras: Bundle?
): Uri?
Implement this to handle requests to insert a new row. As a courtesy, call notifyChange()
after inserting. This method can be called from multiple threads, as described in Processes and Threads.
Parameters | |
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uri |
Uri: The content:// URI of the insertion request. This value cannot be null . |
values |
ContentValues?: A set of column_name/value pairs to add to the database. This value may be null . |
extras |
Bundle?: A Bundle containing additional information necessary for the operation. Arguments may include SQL style arguments, such as ContentResolver#QUERY_ARG_SQL_LIMIT , but note that the documentation for each individual provider will indicate which arguments they support. This value may be null . |
Return | |
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Uri? |
The URI for the newly inserted item. This value may be null . |
Exceptions | |
---|---|
java.lang.IllegalArgumentException |
if the provider doesn't support one of the requested Bundle arguments. |
onCallingPackageChanged
open fun onCallingPackageChanged(): Unit
Called whenever the value of getCallingPackage()
changes, giving the provider an opportunity to invalidate any security related caching it may be performing.
This typically happens when a ContentProvider
makes a nested call back into itself when already processing a call from a remote process.
onConfigurationChanged
open fun onConfigurationChanged(newConfig: Configuration): Unit
Called by the system when the device configuration changes while your component is running. Note that, unlike activities, other components are never restarted when a configuration changes: they must always deal with the results of the change, such as by re-retrieving resources.
At the time that this function has been called, your Resources object will have been updated to return resource values matching the new configuration.
For more information, read Handling Runtime Changes. This method is always called on the application main thread, and must not perform lengthy operations.
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.)
Parameters | |
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newConfig |
Configuration: The new device configuration. This value cannot be null . |
onCreate
abstract fun onCreate(): Boolean
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.
You should defer nontrivial initialization (such as opening, upgrading, and scanning databases) until the content provider is used (via #query, #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.
If you use SQLite, 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 android.database.sqlite.SQLiteOpenHelper#getReadableDatabase
or android.database.sqlite.SQLiteOpenHelper#getWritableDatabase
from this method. (Instead, override android.database.sqlite.SQLiteOpenHelper#onOpen
to initialize the database when it is first opened.)
Return | |
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Boolean |
true if the provider was successfully loaded, false otherwise |
onLowMemory
open fun onLowMemory(): Unit
This is called when the overall system is running low on memory, and actively running processes should trim their memory usage. While the exact point at which this will be called is not defined, generally it will happen when all background process have been killed. That is, before reaching the point of killing processes hosting service and foreground UI that we would like to avoid killing. This method is always called on the application main thread, and must not perform lengthy operations.
The default content provider implementation does nothing. Subclasses may override this method to take appropriate action.
onTrimMemory
open fun onTrimMemory(level: Int): Unit
Parameters | |
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level |
Int: The context of the trim, giving a hint of the amount of trimming the application may like to perform. Value is android.content.ComponentCallbacks2#TRIM_MEMORY_COMPLETE , android.content.ComponentCallbacks2#TRIM_MEMORY_MODERATE , android.content.ComponentCallbacks2#TRIM_MEMORY_BACKGROUND , android.content.ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN , android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_CRITICAL , android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_LOW , or android.content.ComponentCallbacks2#TRIM_MEMORY_RUNNING_MODERATE |
openAssetFile
open fun openAssetFile(
uri: Uri,
mode: String
): AssetFileDescriptor?
This is like #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 Processes and Threads.
If you implement this, your clients must be able to deal with such file slices, either directly with android.content.ContentResolver#openAssetFileDescriptor, or by using the higher-level ContentResolver.openInputStream
or android.content.ContentResolver#openOutputStream methods.
The returned AssetFileDescriptor can be a pipe or socket pair to enable streaming of data.
If you are implementing this to return a full file, you should create the AssetFileDescriptor with AssetFileDescriptor#UNKNOWN_LENGTH
to be compatible with applications that cannot handle sub-sections of files.
For use in Intents, you will want to implement getType
to return the appropriate MIME type for the data returned here with the same URI. This will allow intent resolution to automatically determine the data MIME type and select the appropriate matching targets as part of its operation.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
.
Parameters | |
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uri |
Uri: The URI whose file is to be opened. This value cannot be null . |
mode |
String: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". Please note the exact implementation of these may differ for each Provider implementation - for example, "w" may or may not truncate. This value cannot be null . |
Return | |
---|---|
AssetFileDescriptor? |
Returns a new AssetFileDescriptor which you can use to access the file. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the file. |
openAssetFile
open fun openAssetFile(
uri: Uri,
mode: String,
signal: CancellationSignal?
): AssetFileDescriptor?
This is like #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 Processes and Threads.
If you implement this, your clients must be able to deal with such file slices, either directly with android.content.ContentResolver#openAssetFileDescriptor, or by using the higher-level ContentResolver.openInputStream
or android.content.ContentResolver#openOutputStream methods.
The returned AssetFileDescriptor can be a pipe or socket pair to enable streaming of data.
If you are implementing this to return a full file, you should create the AssetFileDescriptor with AssetFileDescriptor#UNKNOWN_LENGTH
to be compatible with applications that cannot handle sub-sections of files.
For use in Intents, you will want to implement getType
to return the appropriate MIME type for the data returned here with the same URI. This will allow intent resolution to automatically determine the data MIME type and select the appropriate matching targets as part of its operation.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
.
Parameters | |
---|---|
uri |
Uri: The URI whose file is to be opened. This value cannot be null . |
mode |
String: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". Please note the exact implementation of these may differ for each Provider implementation - for example, "w" may or may not truncate. This value cannot be null . |
signal |
CancellationSignal?: A signal to cancel the operation in progress, or null if none. For example, if you are downloading a file from the network to service a "rw" mode request, you should periodically call CancellationSignal#throwIfCanceled() to check whether the client has canceled the request and abort the download. |
Return | |
---|---|
AssetFileDescriptor? |
Returns a new AssetFileDescriptor which you can use to access the file. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the file. |
openFile
open fun openFile(
uri: Uri,
mode: String
): ParcelFileDescriptor?
Override this to handle requests to open a file blob. The default implementation always throws FileNotFoundException
. This method can be called from multiple threads, as described in Processes and Threads.
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.
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.
If opened with the exclusive "r" or "w" modes, the returned ParcelFileDescriptor can be a pipe or socket pair to enable streaming of data. Opening with the "rw" or "rwt" modes implies a file on disk that supports seeking.
If you need to detect when the returned ParcelFileDescriptor has been closed, or if the remote process has crashed or encountered some other error, you can use ParcelFileDescriptor#open(File, int,
, ParcelFileDescriptor#createReliablePipe()
, or ParcelFileDescriptor#createReliableSocketPair()
.
If you need to return a large file that isn't backed by a real file on disk, such as a file on a network share or cloud storage service, consider using StorageManager#openProxyFileDescriptor(int, android.os.ProxyFileDescriptorCallback, android.os.Handler)
which will let you to stream the content on-demand.
For use in Intents, you will want to implement getType
to return the appropriate MIME type for the data returned here with the same URI. This will allow intent resolution to automatically determine the data MIME type and select the appropriate matching targets as part of its operation.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
. You may also want to support other common columns if you have additional meta-data to supply, such as android.provider.MediaStore.MediaColumns#DATE_ADDED
in android.provider.MediaStore.MediaColumns
.
Parameters | |
---|---|
uri |
Uri: The URI whose file is to be opened. This value cannot be null . |
mode |
String: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". Please note the exact implementation of these may differ for each Provider implementation - for example, "w" may or may not truncate. This value cannot be null . |
Return | |
---|---|
ParcelFileDescriptor? |
Returns a new ParcelFileDescriptor which you can use to access the file. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the file. |
openFile
open fun openFile(
uri: Uri,
mode: String,
signal: CancellationSignal?
): ParcelFileDescriptor?
Override this to handle requests to open a file blob. The default implementation always throws FileNotFoundException
. This method can be called from multiple threads, as described in Processes and Threads.
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.
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.
If opened with the exclusive "r" or "w" modes, the returned ParcelFileDescriptor can be a pipe or socket pair to enable streaming of data. Opening with the "rw" or "rwt" modes implies a file on disk that supports seeking.
If you need to detect when the returned ParcelFileDescriptor has been closed, or if the remote process has crashed or encountered some other error, you can use ParcelFileDescriptor#open(File, int,
, ParcelFileDescriptor#createReliablePipe()
, or ParcelFileDescriptor#createReliableSocketPair()
.
For use in Intents, you will want to implement getType
to return the appropriate MIME type for the data returned here with the same URI. This will allow intent resolution to automatically determine the data MIME type and select the appropriate matching targets as part of its operation.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
. You may also want to support other common columns if you have additional meta-data to supply, such as android.provider.MediaStore.MediaColumns#DATE_ADDED
in android.provider.MediaStore.MediaColumns
.
Parameters | |
---|---|
uri |
Uri: The URI whose file is to be opened. This value cannot be null . |
mode |
String: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". Please note the exact implementation of these may differ for each Provider implementation - for example, "w" may or may not truncate. This value cannot be null . |
signal |
CancellationSignal?: A signal to cancel the operation in progress, or null if none. For example, if you are downloading a file from the network to service a "rw" mode request, you should periodically call CancellationSignal#throwIfCanceled() to check whether the client has canceled the request and abort the download. |
Return | |
---|---|
ParcelFileDescriptor? |
Returns a new ParcelFileDescriptor which you can use to access the file. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the file. |
openPipeHelper
open fun <T : Any!> openPipeHelper(
uri: Uri,
mimeType: String,
opts: Bundle?,
args: T?,
func: ContentProvider.PipeDataWriter<T>
): ParcelFileDescriptor
A helper function for implementing #openTypedAssetFile, for creating a data pipe and background thread allowing you to stream generated data back to the client. This function returns a new ParcelFileDescriptor that should be returned to the caller (the caller is responsible for closing it).
Parameters | |
---|---|
uri |
Uri: The URI whose data is to be written. This value cannot be null . |
mimeType |
String: The desired type of data to be written. This value cannot be null . |
opts |
Bundle?: Options supplied by caller. This value may be null . |
args |
T?: Your own custom arguments. This value may be null . |
func |
ContentProvider.PipeDataWriter<T>: Interface implementing the function that will actually stream the data. This value cannot be null . |
Return | |
---|---|
ParcelFileDescriptor |
Returns a new ParcelFileDescriptor holding the read side of the pipe. This should be returned to the caller for reading; the caller is responsible for closing it when done. This value cannot be null . |
openTypedAssetFile
open fun openTypedAssetFile(
uri: Uri,
mimeTypeFilter: String,
opts: Bundle?
): AssetFileDescriptor?
Called by a client to open a read-only stream containing data of a particular MIME type. This is like openAssetFile(android.net.Uri,java.lang.String)
, except the file can only be read-only and the content provider may perform data conversions to generate data of the desired type.
The default implementation compares the given mimeType against the result of getType(android.net.Uri)
and, if they match, simply calls openAssetFile(android.net.Uri,java.lang.String)
.
See ClipData
for examples of the use and implementation of this method.
The returned AssetFileDescriptor can be a pipe or socket pair to enable streaming of data.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
. You may also want to support other common columns if you have additional meta-data to supply, such as android.provider.MediaStore.MediaColumns#DATE_ADDED
in android.provider.MediaStore.MediaColumns
.
Parameters | |
---|---|
uri |
Uri: The data in the content provider being queried. This value cannot be null . |
mimeTypeFilter |
String: The type of data the client desires. May be a pattern, such as */*, if the caller does not have specific type requirements; in this case the content provider will pick its best type matching the pattern. This value cannot be null . |
opts |
Bundle?: Additional options from the client. The definitions of these are specific to the content provider being called. This value may be null . |
Return | |
---|---|
AssetFileDescriptor? |
Returns a new AssetFileDescriptor from which the client can read data of the desired type. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the data. |
java.lang.IllegalArgumentException |
Throws IllegalArgumentException if the content provider does not support the requested MIME type. |
openTypedAssetFile
open fun openTypedAssetFile(
uri: Uri,
mimeTypeFilter: String,
opts: Bundle?,
signal: CancellationSignal?
): AssetFileDescriptor?
Called by a client to open a read-only stream containing data of a particular MIME type. This is like openAssetFile(android.net.Uri,java.lang.String)
, except the file can only be read-only and the content provider may perform data conversions to generate data of the desired type.
The default implementation compares the given mimeType against the result of getType(android.net.Uri)
and, if they match, simply calls openAssetFile(android.net.Uri,java.lang.String)
.
See ClipData
for examples of the use and implementation of this method.
The returned AssetFileDescriptor can be a pipe or socket pair to enable streaming of data.
For better interoperability with other applications, it is recommended that for any URIs that can be opened, you also support queries on them containing at least the columns specified by android.provider.OpenableColumns
. You may also want to support other common columns if you have additional meta-data to supply, such as android.provider.MediaStore.MediaColumns#DATE_ADDED
in android.provider.MediaStore.MediaColumns
.
Parameters | |
---|---|
uri |
Uri: The data in the content provider being queried. This value cannot be null . |
mimeTypeFilter |
String: The type of data the client desires. May be a pattern, such as */*, if the caller does not have specific type requirements; in this case the content provider will pick its best type matching the pattern. This value cannot be null . |
opts |
Bundle?: Additional options from the client. The definitions of these are specific to the content provider being called. This value may be null . |
signal |
CancellationSignal?: A signal to cancel the operation in progress, or null if none. For example, if you are downloading a file from the network to service a "rw" mode request, you should periodically call CancellationSignal#throwIfCanceled() to check whether the client has canceled the request and abort the download. |
Return | |
---|---|
AssetFileDescriptor? |
Returns a new AssetFileDescriptor from which the client can read data of the desired type. This value may be null . |
Exceptions | |
---|---|
java.io.FileNotFoundException |
Throws FileNotFoundException if there is no file associated with the given URI or the mode is invalid. |
java.lang.SecurityException |
Throws SecurityException if the caller does not have permission to access the data. |
java.lang.IllegalArgumentException |
Throws IllegalArgumentException if the content provider does not support the requested MIME type. |
query
abstract fun query(
uri: Uri,
projection: Array<String!>?,
selection: String?,
selectionArgs: Array<String!>?,
sortOrder: String?
): Cursor?
Implement this to handle query requests from clients.
Apps targeting android.os.Build.VERSION_CODES#O
or higher should override query(android.net.Uri,java.lang.String[],android.os.Bundle,android.os.CancellationSignal)
and provide a stub implementation of this method.
This method can be called from multiple threads, as described in Processes and Threads.
Example client call:
// 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.
// SQLiteQueryBuilder is a helper class that creates the // proper SQL syntax for us. SQLiteQueryBuilder qBuilder = new SQLiteQueryBuilder(); // Guard against SQL injection attacks qBuilder.setStrict(true); qBuilder.setProjectionMap(MAP_OF_QUERYABLE_COLUMNS); qBuilder.setStrictColumns(true); qBuilder.setStrictGrammar(true); // 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;
Parameters | |
---|---|
uri |
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. This value cannot be null . |
projection |
Array<String!>?: The list of columns to put into the cursor. If null all columns are included. |
selection |
String?: A selection criteria to apply when filtering rows. If null then all rows are included. |
selectionArgs |
Array<String!>?: 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. This value may be null . |
sortOrder |
String?: How the rows in the cursor should be sorted. If null then the provider is free to define the sort order. |
Return | |
---|---|
Cursor? |
a Cursor or null . |
query
open fun query(
uri: Uri,
projection: Array<String!>?,
selection: String?,
selectionArgs: Array<String!>?,
sortOrder: String?,
cancellationSignal: CancellationSignal?
): Cursor?
Implement this to handle query requests from clients with support for cancellation.
Apps targeting android.os.Build.VERSION_CODES#O
or higher should override query(android.net.Uri,java.lang.String[],android.os.Bundle,android.os.CancellationSignal)
instead of this method.
This method can be called from multiple threads, as described in Processes and Threads.
Example client call:
// 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.
// SQLiteQueryBuilder is a helper class that creates the // proper SQL syntax for us. SQLiteQueryBuilder qBuilder = new SQLiteQueryBuilder(); // Guard against SQL injection attacks qBuilder.setStrict(true); qBuilder.setProjectionMap(MAP_OF_QUERYABLE_COLUMNS); qBuilder.setStrictColumns(true); qBuilder.setStrictGrammar(true); // 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;
If you implement this method then you must also implement the version of query(android.net.Uri,java.lang.String[],java.lang.String,java.lang.String[],java.lang.String)
that does not take a cancellation signal to ensure correct operation on older versions of the Android Framework in which the cancellation signal overload was not available.
Parameters | |
---|---|
uri |
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. This value cannot be null . |
projection |
Array<String!>?: The list of columns to put into the cursor. If null all columns are included. |
selection |
String?: A selection criteria to apply when filtering rows. If null then all rows are included. |
selectionArgs |
Array<String!>?: 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. This value may be null . |
sortOrder |
String?: How the rows in the cursor should be sorted. If null then the provider is free to define the sort order. |
cancellationSignal |
CancellationSignal?: A signal to cancel the operation in progress, or null if none. If the operation is canceled, then android.os.OperationCanceledException will be thrown when the query is executed. |
Return | |
---|---|
Cursor? |
a Cursor or null . |
query
open fun query(
uri: Uri,
projection: Array<String!>?,
queryArgs: Bundle?,
cancellationSignal: CancellationSignal?
): Cursor?
Implement this to handle query requests where the arguments are packed into a Bundle
. Arguments may include traditional SQL style query arguments. When present these should be handled according to the contract established in query(android.net.Uri,java.lang.String[],java.lang.String,java.lang.String[],java.lang.String,android.os.CancellationSignal)
.
Traditional SQL arguments can be found in the bundle using the following keys:
android.content.ContentResolver#QUERY_ARG_SQL_SELECTION
android.content.ContentResolver#QUERY_ARG_SQL_SELECTION_ARGS
android.content.ContentResolver#QUERY_ARG_SQL_SORT_ORDER
This method can be called from multiple threads, as described in Processes and Threads.
Example client call:
// Request 20 records starting at row index 30. Bundle queryArgs = new Bundle(); queryArgs.putInt(ContentResolver.QUERY_ARG_OFFSET, 30); queryArgs.putInt(ContentResolver.QUERY_ARG_LIMIT, 20); Cursor cursor = getContentResolver().query( contentUri, // Content Uri is specific to individual content providers. projection, // String[] describing which columns to return. queryArgs, // Query arguments. null); // Cancellation signal.
int recordsetSize = 0x1000; // Actual value is implementation specific. queryArgs = queryArgs != null ? queryArgs : Bundle.EMPTY; // ensure queryArgs is non-null int offset = queryArgs.getInt(ContentResolver.QUERY_ARG_OFFSET, 0); int limit = queryArgs.getInt(ContentResolver.QUERY_ARG_LIMIT, Integer.MIN_VALUE); MatrixCursor c = new MatrixCursor(PROJECTION, limit); // Calculate the number of items to include in the cursor. int numItems = MathUtils.constrain(recordsetSize - offset, 0, limit); // Build the paged result set.... for (int i = offset; i < offset + numItems; i++) { // populate row from your data. } Bundle extras = new Bundle(); c.setExtras(extras); // Any QUERY_ARG_* key may be included if honored. // In an actual implementation, include only keys that are both present in queryArgs // and reflected in the Cursor output. For example, if QUERY_ARG_OFFSET were included // in queryArgs, but was ignored because it contained an invalid value (like –273), // then QUERY_ARG_OFFSET should be omitted. extras.putStringArray(ContentResolver.EXTRA_HONORED_ARGS, new String[] { ContentResolver.QUERY_ARG_OFFSET, ContentResolver.QUERY_ARG_LIMIT }); extras.putInt(ContentResolver.EXTRA_TOTAL_COUNT, recordsetSize); cursor.setNotificationUri(getContext().getContentResolver(), uri); return cursor;
See query(android.net.Uri,java.lang.String[],java.lang.String,java.lang.String[],java.lang.String,android.os.CancellationSignal)
for implementation details.
Parameters | |
---|---|
uri |
Uri: The URI to query. This will be the full URI sent by the client. This value cannot be null . |
projection |
Array<String!>?: The list of columns to put into the cursor. If null provide a default set of columns. |
queryArgs |
Bundle?: A Bundle containing additional information necessary for the operation. Arguments may include SQL style arguments, such as ContentResolver#QUERY_ARG_SQL_LIMIT , but note that the documentation for each individual provider will indicate which arguments they support. This value may be null . |
cancellationSignal |
CancellationSignal?: A signal to cancel the operation in progress, or null . |
Return | |
---|---|
Cursor? |
a Cursor or null . |
refresh
open fun refresh(
uri: Uri!,
extras: Bundle?,
cancellationSignal: CancellationSignal?
): Boolean
Implement this to support refresh of content identified by uri
. By default, this method returns false; providers who wish to implement this should return true to signal the client that the provider has tried refreshing with its own implementation.
This allows clients to request an explicit refresh of content identified by uri
.
Client code should only invoke this method when there is a strong indication (such as a user initiated pull to refresh gesture) that the content is stale.
Remember to send ContentResolver#notifyChange(Uri, android.database.ContentObserver)
notifications when content changes.
Parameters | |
---|---|
uri |
Uri!: The Uri identifying the data to refresh. |
extras |
Bundle?: Additional options from the client. The definitions of these are specific to the content provider being called. This value may be null . |
cancellationSignal |
CancellationSignal?: A signal to cancel the operation in progress, or null if none. For example, if you called refresh on a particular uri, you should call CancellationSignal#throwIfCanceled() to check whether the client has canceled the refresh request. |
Return | |
---|---|
Boolean |
true if the provider actually tried refreshing. |
requireContext
fun requireContext(): Context
Retrieves a Non-Nullable Context this provider is running in, this is intended to be called after onCreate
. When called before context was created, an IllegalStateException will be thrown.
Note A provider must be declared in the manifest and created automatically by the system, and context is only available after onCreate
is called.
Return | |
---|---|
Context |
This value cannot be null . |
restoreCallingIdentity
fun restoreCallingIdentity(identity: ContentProvider.CallingIdentity): Unit
Restore the identity of the incoming IPC on the current thread back to a previously identity that was returned by clearCallingIdentity
.
Internally this calls Binder#restoreCallingIdentity(long)
and also restores any value stored in getCallingPackage()
.
Parameters | |
---|---|
identity |
ContentProvider.CallingIdentity: This value cannot be null . |
shutdown
open fun shutdown(): Unit
Implement this to shut down the ContentProvider instance. You can then invoke this method in unit tests.
Android normally handles ContentProvider startup and shutdown automatically. You do not need to start up or shut down a ContentProvider. When you invoke a test method on a ContentProvider, however, a ContentProvider instance is started and keeps running after the test finishes, even if a succeeding test instantiates another ContentProvider. A conflict develops because the two instances are usually running against the same underlying data source (for example, an sqlite database).
Implementing shutDown() avoids this conflict by providing a way to terminate the ContentProvider. This method can also prevent memory leaks from multiple instantiations of the ContentProvider, and it can ensure unit test isolation by allowing you to completely clean up the test fixture before moving on to the next test.
uncanonicalize
open fun uncanonicalize(url: Uri): Uri?
Remove canonicalization from canonical URIs previously returned by canonicalize
. For example, if your implementation is to add a query param to canonicalize a URI, this method can simply trip any query params on the URI. The default implementation always returns the same url that was passed in.
Parameters | |
---|---|
url |
Uri: The Uri to remove any canonicalization from. This value cannot be null . |
Return | |
---|---|
Uri? |
Return the non-canonical representation of url, return the url as-is if there is nothing to do, or return null if the data identified by the canonical representation can not be found in the current environment. |
update
abstract fun update(
uri: Uri,
values: ContentValues?,
selection: String?,
selectionArgs: Array<String!>?
): Int
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 notifyChange()
after updating. This method can be called from multiple threads, as described in Processes and Threads.
Parameters | |
---|---|
uri |
Uri: The URI to query. This can potentially have a record ID if this is an update request for a specific record. This value cannot be null . |
values |
ContentValues?: A set of column_name/value pairs to update in the database. This value may be null . |
selection |
String?: An optional filter to match rows to update. This value may be null . |
selectionArgs |
Array<String!>?: This value may be null . |
Return | |
---|---|
Int |
the number of rows affected. |
update
open fun update(
uri: Uri,
values: ContentValues?,
extras: Bundle?
): Int
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 notifyChange()
after updating. This method can be called from multiple threads, as described in Processes and Threads.
Parameters | |
---|---|
uri |
Uri: The URI to query. This can potentially have a record ID if this is an update request for a specific record. This value cannot be null . |
values |
ContentValues?: A set of column_name/value pairs to update in the database. This value may be null . |
extras |
Bundle?: A Bundle containing additional information necessary for the operation. Arguments may include SQL style arguments, such as ContentResolver#QUERY_ARG_SQL_LIMIT , but note that the documentation for each individual provider will indicate which arguments they support. This value may be null . |
Return | |
---|---|
Int |
the number of rows affected. |
Exceptions | |
---|---|
java.lang.IllegalArgumentException |
if the provider doesn't support one of the requested Bundle arguments. |
Protected methods
isTemporary
protected open fun isTemporary(): Boolean
Returns true if this instance is a temporary content provider.
Return | |
---|---|
Boolean |
true if this instance is a temporary content provider |
openFileHelper
protected fun openFileHelper(
uri: Uri,
mode: String
): ParcelFileDescriptor
Convenience for subclasses that wish to implement #openFile by looking up a column named "_data" at the given URI.
Parameters | |
---|---|
uri |
Uri: The URI to be opened. This value cannot be null . |
mode |
String: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". Please note the exact implementation of these may differ for each Provider implementation - for example, "w" may or may not truncate. This value cannot be null . |
Return | |
---|---|
ParcelFileDescriptor |
Returns a new ParcelFileDescriptor that can be used by the client to access the file. This value cannot be null . |
setPathPermissions
protected fun setPathPermissions(permissions: Array<PathPermission!>?): Unit
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.
Parameters | |
---|---|
permissions |
Array<PathPermission!>?: Array of path permission descriptions. This value may be null . |
setReadPermission
protected fun setReadPermission(permission: String?): Unit
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.
Parameters | |
---|---|
permission |
String?: Name of the permission required for read-only access. This value may be null . |
setWritePermission
protected fun setWritePermission(permission: String?): Unit
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.
Parameters | |
---|---|
permission |
String?: Name of the permission required for read/write access. This value may be null . |