Added in API level 1

Summary: Constants | Methods | Inherited Methods

Cursor

Kotlin |Java

public interface Cursor
implements Closeable

android.database.Cursor

Known indirect subclasses

AbstractCursor, AbstractWindowedCursor, CrossProcessCursor, CrossProcessCursorWrapper, CursorWrapper, MatrixCursor, MergeCursor, MockCursor, SQLiteCursor

AbstractCursor	This is an abstract cursor class that handles a lot of the common code that all cursors need to deal with and is provided for convenience reasons.
AbstractWindowedCursor	A base class for Cursors that store their data in `CursorWindow`s.
CrossProcessCursor	A cross process cursor is an extension of a `Cursor` that also supports usage from remote processes.
CrossProcessCursorWrapper	Cursor wrapper that implements `CrossProcessCursor`.
CursorWrapper	Wrapper class for Cursor that delegates all calls to the actual cursor object.
MatrixCursor	A mutable cursor implementation backed by an array of `Object`s.
MergeCursor	A convenience class that lets you present an array of Cursors as a single linear Cursor.
MockCursor	This class was deprecated in API level 24. Use a mocking framework like Mockito. New tests should be written using the Android Testing Support Library.
SQLiteCursor	A Cursor implementation that exposes results from a query on a `SQLiteDatabase`.

This interface provides random read-write access to the result set returned by a database query.

Cursor implementations are not required to be synchronized so code using a Cursor from multiple threads should perform its own synchronization when using the Cursor.

Implementations should subclass AbstractCursor.

Summary

Constants
`int`	`FIELD_TYPE_BLOB` Value returned by `getType(int)` if the specified column type is blob
`int`	`FIELD_TYPE_FLOAT` Value returned by `getType(int)` if the specified column type is float
`int`	`FIELD_TYPE_INTEGER` Value returned by `getType(int)` if the specified column type is integer
`int`	`FIELD_TYPE_NULL` Value returned by `getType(int)` if the specified column is null
`int`	`FIELD_TYPE_STRING` Value returned by `getType(int)` if the specified column type is string

Public methods
`abstract void`	`close()` Closes the Cursor, releasing all of its resources and making it completely invalid.
`abstract void`	`copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)` Retrieves the requested column text and stores it in the buffer provided.
`abstract void`	`deactivate()` This method was deprecated in API level 16. Since `requery()` is deprecated, so too is this.
`abstract byte[]`	`getBlob(int columnIndex)` Returns the value of the requested column as a byte array.
`abstract int`	`getColumnCount()` Return total number of columns
`abstract int`	`getColumnIndex(String columnName)` Returns the zero-based index for the given column name, or -1 if the column doesn't exist.
`abstract int`	`getColumnIndexOrThrow(String columnName)` Returns the zero-based index for the given column name, or throws `IllegalArgumentException` if the column doesn't exist.
`abstract String`	`getColumnName(int columnIndex)` Returns the column name at the given zero-based column index.
`abstract String[]`	`getColumnNames()` Returns a string array holding the names of all of the columns in the result set in the order in which they were listed in the result.
`abstract int`	`getCount()` Returns the numbers of rows in the cursor.
`abstract double`	`getDouble(int columnIndex)` Returns the value of the requested column as a double.
`abstract Bundle`	`getExtras()` Returns a bundle of extra values.
`abstract float`	`getFloat(int columnIndex)` Returns the value of the requested column as a float.
`abstract int`	`getInt(int columnIndex)` Returns the value of the requested column as an int.
`abstract long`	`getLong(int columnIndex)` Returns the value of the requested column as a long.
`abstract Uri`	`getNotificationUri()` Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by `setNotificationUri(ContentResolver, Uri)`.
`default List<Uri>`	`getNotificationUris()` Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by `setNotificationUris(ContentResolver, List)`.
`abstract int`	`getPosition()` Returns the current position of the cursor in the row set.
`abstract short`	`getShort(int columnIndex)` Returns the value of the requested column as a short.
`abstract String`	`getString(int columnIndex)` Returns the value of the requested column as a String.
`abstract int`	`getType(int columnIndex)` Returns data type of the given column's value.
`abstract boolean`	`getWantsAllOnMoveCalls()` onMove() will only be called across processes if this method returns true.
`abstract boolean`	`isAfterLast()` Returns whether the cursor is pointing to the position after the last row.
`abstract boolean`	`isBeforeFirst()` Returns whether the cursor is pointing to the position before the first row.
`abstract boolean`	`isClosed()` return true if the cursor is closed
`abstract boolean`	`isFirst()` Returns whether the cursor is pointing to the first row.
`abstract boolean`	`isLast()` Returns whether the cursor is pointing to the last row.
`abstract boolean`	`isNull(int columnIndex)` Returns `true` if the value in the indicated column is null.
`abstract boolean`	`move(int offset)` Move the cursor by a relative amount, forward or backward, from the current position.
`abstract boolean`	`moveToFirst()` Move the cursor to the first row.
`abstract boolean`	`moveToLast()` Move the cursor to the last row.
`abstract boolean`	`moveToNext()` Move the cursor to the next row.
`abstract boolean`	`moveToPosition(int position)` Move the cursor to an absolute position.
`abstract boolean`	`moveToPrevious()` Move the cursor to the previous row.
`abstract void`	`registerContentObserver(ContentObserver observer)` Register an observer that is called when changes happen to the content backing this cursor.
`abstract void`	`registerDataSetObserver(DataSetObserver observer)` Register an observer that is called when changes happen to the contents of the this cursors data set, for example, when the data set is changed via `requery()`, `deactivate()`, or `close()`.
`abstract boolean`	`requery()` This method was deprecated in API level 15. Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back.
`abstract Bundle`	`respond(Bundle extras)` This is an out-of-band way for the user of a cursor to communicate with the cursor.
`abstract void`	`setExtras(Bundle extras)` Sets a `Bundle` that will be returned by `getExtras()`.
`abstract void`	`setNotificationUri(ContentResolver cr, Uri uri)` Register to watch a content URI for changes.
`default void`	`setNotificationUris(ContentResolver cr, List<Uri> uris)` Similar to `setNotificationUri(android.content.ContentResolver, android.net.Uri)`, except this version allows to watch multiple content URIs for changes.
`abstract void`	`unregisterContentObserver(ContentObserver observer)` Unregister an observer that has previously been registered with this cursor via `registerContentObserver(ContentObserver)`.
`abstract void`	`unregisterDataSetObserver(DataSetObserver observer)` Unregister an observer that has previously been registered with this cursor via `registerContentObserver(ContentObserver)`.

Inherited methods

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Constants

FIELD_TYPE_BLOB

Added in API level 11

public static final int FIELD_TYPE_BLOB

Value returned by getType(int) if the specified column type is blob

Constant Value: 4 (0x00000004)

FIELD_TYPE_FLOAT

Added in API level 11

public static final int FIELD_TYPE_FLOAT

Value returned by getType(int) if the specified column type is float

Constant Value: 2 (0x00000002)

FIELD_TYPE_INTEGER

Added in API level 11

public static final int FIELD_TYPE_INTEGER

Value returned by getType(int) if the specified column type is integer

Constant Value: 1 (0x00000001)

FIELD_TYPE_NULL

Added in API level 11

public static final int FIELD_TYPE_NULL

Value returned by getType(int) if the specified column is null

Constant Value: 0 (0x00000000)

FIELD_TYPE_STRING

Added in API level 11

public static final int FIELD_TYPE_STRING

Value returned by getType(int) if the specified column type is string

Constant Value: 3 (0x00000003)

Public methods

close

Added in API level 1

public abstract void close ()

Closes the Cursor, releasing all of its resources and making it completely invalid. Unlike deactivate() a call to requery() will not make the Cursor valid again.

copyStringToBuffer

Added in API level 1

public abstract void copyStringToBuffer (int columnIndex, 
                CharArrayBuffer buffer)

Retrieves the requested column text and stores it in the buffer provided. If the buffer size is not sufficient, a new char buffer will be allocated and assigned to CharArrayBuffer.data

Parameters
`columnIndex`	`int`: the zero-based index of the target column. if the target column is null, return buffer Value is 0 or greater
`buffer`	`CharArrayBuffer`: the buffer to copy the text into.

deactivate

Added in API level 1
Deprecated in API level 16

public abstract void deactivate ()

This method was deprecated in API level 16.
Since requery() is deprecated, so too is this.

Deactivates the Cursor, making all calls on it fail until requery() is called. Inactive Cursors use fewer resources than active Cursors. Calling requery() will make the cursor active again.

getBlob

Added in API level 1

public abstract byte[] getBlob (int columnIndex)

Returns the value of the requested column as a byte array.

The result and whether this method throws an exception when the column value is null or the column type is not a blob type is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`byte[]`	the value of that column as a byte array.

getColumnCount

Added in API level 1

public abstract int getColumnCount ()

Return total number of columns

Returns
`int`	number of columns Value is 0 or greater

getColumnIndex

Added in API level 1

public abstract int getColumnIndex (String columnName)

Returns the zero-based index for the given column name, or -1 if the column doesn't exist. If you expect the column to exist use getColumnIndexOrThrow(java.lang.String) instead, which will make the error more clear.

Parameters
`columnName`	`String`: the name of the target column.

Returns
`int`	the zero-based column index for the given column name, or -1 if the column name does not exist. Value is -1 or greater

See also:

getColumnIndexOrThrow(String)

getColumnIndexOrThrow

Added in API level 1

public abstract int getColumnIndexOrThrow (String columnName)

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist. If you're not sure if a column will exist or not use getColumnIndex(java.lang.String) and check for -1, which is more efficient than catching the exceptions.

Parameters
`columnName`	`String`: the name of the target column.

Returns
`int`	the zero-based column index for the given column name Value is 0 or greater

Throws
`IllegalArgumentException`	if the column does not exist

See also:

getColumnIndex(String)

getColumnName

Added in API level 1

public abstract String getColumnName (int columnIndex)

Returns the column name at the given zero-based column index.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`String`	the column name for the given column index.

getColumnNames

Added in API level 1

public abstract String[] getColumnNames ()

Returns a string array holding the names of all of the columns in the result set in the order in which they were listed in the result.

Returns
`String[]`	the names of the columns returned in this query.

getCount

Added in API level 1

public abstract int getCount ()

Returns the numbers of rows in the cursor.

Returns
`int`	the number of rows in the cursor. Value is 0 or greater

getDouble

Added in API level 1

public abstract double getDouble (int columnIndex)

Returns the value of the requested column as a double.

The result and whether this method throws an exception when the column value is null, the column type is not a floating-point type, or the floating-point value is not representable as a double value is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`double`	the value of that column as a double.

getExtras

Added in API level 1

public abstract Bundle getExtras ()

Returns a bundle of extra values. This is an optional way for cursors to provide out-of-band metadata to their users. One use of this is for reporting on the progress of network requests that are required to fetch data for the cursor.

These values may only change when requery is called.

Returns
`Bundle`	cursor-defined values, or `Bundle.EMPTY` if there are no values. Never `null`.

getFloat

Added in API level 1

public abstract float getFloat (int columnIndex)

Returns the value of the requested column as a float.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`float`	the value of that column as a float.

getInt

Added in API level 1

public abstract int getInt (int columnIndex)

Returns the value of the requested column as an int.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Integer.MIN_VALUE, Integer.MAX_VALUE] is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`int`	the value of that column as an int.

getLong

Added in API level 1

public abstract long getLong (int columnIndex)

Returns the value of the requested column as a long.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Long.MIN_VALUE, Long.MAX_VALUE] is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`long`	the value of that column as a long.

getNotificationUri

Added in API level 19

public abstract Uri getNotificationUri ()

Return the URI at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUri(ContentResolver, Uri).

Returns
`Uri`	Returns a URI that can be used with `ContentResolver.registerContentObserver` to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getNotificationUris

Added in API level 29

public List<Uri> getNotificationUris ()

Return the URIs at which notifications of changes in this Cursor's data will be delivered, as previously set by setNotificationUris(ContentResolver, List).

If this is not implemented, this is equivalent to calling getNotificationUri().

Returns
`List<Uri>`	Returns URIs that can be used with `ContentResolver.registerContentObserver` to find out about changes to this Cursor's data. May be null if no notification URI has been set.

getPosition

Added in API level 1

public abstract int getPosition ()

Returns the current position of the cursor in the row set. The value is zero-based. When the row set is first returned the cursor will be at positon -1, which is before the first row. After the last row is returned another call to next() will leave the cursor past the last entry, at a position of count().

Returns
`int`	the current cursor position. Value is -1 or greater

getShort

Added in API level 1

public abstract short getShort (int columnIndex)

Returns the value of the requested column as a short.

The result and whether this method throws an exception when the column value is null, the column type is not an integral type, or the integer value is outside the range [Short.MIN_VALUE, Short.MAX_VALUE] is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`short`	the value of that column as a short.

getString

Added in API level 1

public abstract String getString (int columnIndex)

Returns the value of the requested column as a String.

The result and whether this method throws an exception when the column value is null or the column type is not a string type is implementation-defined.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`String`	the value of that column as a String.

getType

Added in API level 11

public abstract int getType (int columnIndex)

Returns data type of the given column's value. The preferred type of the column is returned but the data may be converted to other types as documented in the get-type methods such as getInt(int), getFloat(int) etc.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`int`	column value type Value is `FIELD_TYPE_NULL`, `FIELD_TYPE_INTEGER`, `FIELD_TYPE_FLOAT`, `FIELD_TYPE_STRING`, or `FIELD_TYPE_BLOB`

getWantsAllOnMoveCalls

Added in API level 1

public abstract boolean getWantsAllOnMoveCalls ()

onMove() will only be called across processes if this method returns true.

Returns
`boolean`	whether all cursor movement should result in a call to onMove().

isAfterLast

Added in API level 1

public abstract boolean isAfterLast ()

Returns whether the cursor is pointing to the position after the last row.

Returns
`boolean`	whether the cursor is after the last result.

isBeforeFirst

Added in API level 1

public abstract boolean isBeforeFirst ()

Returns whether the cursor is pointing to the position before the first row.

Returns
`boolean`	whether the cursor is before the first result.

isClosed

Added in API level 1

public abstract boolean isClosed ()

return true if the cursor is closed

Returns
`boolean`	true if the cursor is closed.

isFirst

Added in API level 1

public abstract boolean isFirst ()

Returns whether the cursor is pointing to the first row.

Returns
`boolean`	whether the cursor is pointing at the first entry.

isLast

Added in API level 1

public abstract boolean isLast ()

Returns whether the cursor is pointing to the last row.

Returns
`boolean`	whether the cursor is pointing at the last entry.

isNull

Added in API level 1

public abstract boolean isNull (int columnIndex)

Returns true if the value in the indicated column is null.

Parameters
`columnIndex`	`int`: the zero-based index of the target column. Value is 0 or greater

Returns
`boolean`	whether the column value is null.

move

Added in API level 1

public abstract boolean move (int offset)

Move the cursor by a relative amount, forward or backward, from the current position. Positive offsets move forwards, negative offsets move backwards. If the final position is outside of the bounds of the result set then the resultant position will be pinned to -1 or count() depending on whether the value is off the front or end of the set, respectively.

This method will return true if the requested destination was reachable, otherwise, it returns false. For example, if the cursor is at currently on the second entry in the result set and move(-5) is called, the position will be pinned at -1, and false will be returned.

Parameters
`offset`	`int`: the offset to be applied from the current position.

Returns
`boolean`	whether the requested move fully succeeded.

moveToFirst

Added in API level 1

public abstract boolean moveToFirst ()

Move the cursor to the first row.

This method will return false if the cursor is empty.

Returns
`boolean`	whether the move succeeded.

moveToLast

Added in API level 1

public abstract boolean moveToLast ()

Move the cursor to the last row.

This method will return false if the cursor is empty.

Returns
`boolean`	whether the move succeeded.

moveToNext

Added in API level 1

public abstract boolean moveToNext ()

Move the cursor to the next row.

This method will return false if the cursor is already past the last entry in the result set.

Returns
`boolean`	whether the move succeeded.

moveToPosition

Added in API level 1

public abstract boolean moveToPosition (int position)

Move the cursor to an absolute position. The valid range of values is -1 <= position <= count.

This method will return true if the request destination was reachable, otherwise, it returns false.

Parameters
`position`	`int`: the zero-based position to move to. Value is -1 or greater

Returns
`boolean`	whether the requested move fully succeeded.

moveToPrevious

Added in API level 1

public abstract boolean moveToPrevious ()

Move the cursor to the previous row.

This method will return false if the cursor is already before the first entry in the result set.

Returns
`boolean`	whether the move succeeded.

registerContentObserver

Added in API level 1

public abstract void registerContentObserver (ContentObserver observer)

Register an observer that is called when changes happen to the content backing this cursor. Typically the data set won't change until requery() is called.

Parameters
`observer`	`ContentObserver`: the object that gets notified when the content backing the cursor changes.

See also:

unregisterContentObserver(ContentObserver)

registerDataSetObserver

Added in API level 1

public abstract void registerDataSetObserver (DataSetObserver observer)

Register an observer that is called when changes happen to the contents of the this cursors data set, for example, when the data set is changed via requery(), deactivate(), or close().

Parameters
`observer`	`DataSetObserver`: the object that gets notified when the cursors data set changes.

See also:

unregisterDataSetObserver(DataSetObserver)

requery

Added in API level 1
Deprecated in API level 15

public abstract boolean requery ()

This method was deprecated in API level 15.
Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back.

Performs the query that created the cursor again, refreshing its contents. This may be done at any time, including after a call to deactivate(). Since this method could execute a query on the database and potentially take a while, it could cause ANR if it is called on Main (UI) thread. A warning is printed if this method is being executed on Main thread.

Returns
`boolean`	true if the requery succeeded, false if not, in which case the cursor becomes invalid.

respond

Added in API level 1

public abstract Bundle respond (Bundle extras)

This is an out-of-band way for the user of a cursor to communicate with the cursor. The structure of each bundle is entirely defined by the cursor.

One use of this is to tell a cursor that it should retry its network request after it reported an error.

Parameters
`extras`	`Bundle`: extra values, or `Bundle.EMPTY`. Never `null`.

Returns
`Bundle`	extra values, or `Bundle.EMPTY`. Never `null`.

setExtras

Added in API level 23

public abstract void setExtras (Bundle extras)

Sets a Bundle that will be returned by getExtras().

Parameters
`extras`	`Bundle`: `Bundle` to set, or null to set an empty bundle.

setNotificationUri

Added in API level 1

public abstract void setNotificationUri (ContentResolver cr, 
                Uri uri)

Register to watch a content URI for changes. This can be the URI of a specific data row (for example, "content://my_provider_type/23"), or a a generic URI for a content type.

Calling this overrides any previous call to setNotificationUris(android.content.ContentResolver, java.util.List).

Parameters
`cr`	`ContentResolver`: The content resolver from the caller's context. The listener attached to this resolver will be notified.
`uri`	`Uri`: The content URI to watch.

setNotificationUris

Added in API level 29

public void setNotificationUris (ContentResolver cr, 
                List<Uri> uris)

Similar to setNotificationUri(android.content.ContentResolver, android.net.Uri), except this version allows to watch multiple content URIs for changes.

If this is not implemented, this is equivalent to calling setNotificationUri(android.content.ContentResolver, android.net.Uri) with the first URI in uris.

Calling this overrides any previous call to setNotificationUri(android.content.ContentResolver, android.net.Uri).

Parameters
`cr`	`ContentResolver`: The content resolver from the caller's context. The listener attached to this resolver will be notified. This value cannot be `null`.
`uris`	`List`: The content URIs to watch. This value cannot be `null`.

unregisterContentObserver

Added in API level 1

public abstract void unregisterContentObserver (ContentObserver observer)

Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver).

Parameters
`observer`	`ContentObserver`: the object to unregister.

See also:

registerContentObserver(ContentObserver)

unregisterDataSetObserver

Added in API level 1

public abstract void unregisterDataSetObserver (DataSetObserver observer)

Unregister an observer that has previously been registered with this cursor via registerContentObserver(ContentObserver).

Parameters
`observer`	`DataSetObserver`: the object to unregister.

See also:

registerDataSetObserver(DataSetObserver)