MatrixCursor


public class MatrixCursor
extends AbstractCursor

java.lang.Object
   ↳ android.database.AbstractCursor
     ↳ android.database.MatrixCursor


A mutable cursor implementation backed by an array of Objects. Use newRow() to add rows. Automatically expands internal capacity as needed.

Summary

Nested classes

class MatrixCursor.RowBuilder

Builds a row of values using either of these approaches:

  • Values can be added with explicit column ordering using add(java.lang.Object), which starts from the left-most column and adds one column value at a time. 

Inherited 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

Inherited fields

protected boolean mClosed

This field was deprecated in API level 23. Use isClosed() instead.

protected ContentResolver mContentResolver

This field was deprecated in API level 23. Do not use.

protected int mPos

This field was deprecated in API level 23. Use getPosition() instead.

Public constructors

MatrixCursor(String[] columnNames)

Constructs a new cursor.

MatrixCursor(String[] columnNames, int initialCapacity)

Constructs a new cursor with the given initial capacity.

Public methods

void addRow(Object[] columnValues)

Adds a new row to the end with the given column values.

void addRow(Iterable<?> columnValues)

Adds a new row to the end with the given column values.

byte[] getBlob(int column)

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

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.

int getCount()

Returns the numbers of rows in the cursor.

double getDouble(int column)

Returns the value of the requested column as a double.

float getFloat(int column)

Returns the value of the requested column as a float.

int getInt(int column)

Returns the value of the requested column as an int.

long getLong(int column)

Returns the value of the requested column as a long.

short getShort(int column)

Returns the value of the requested column as a short.

String getString(int column)

Returns the value of the requested column as a String.

int getType(int column)

Returns data type of the given column's value.

boolean isNull(int column)

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

MatrixCursor.RowBuilder newRow()

Adds a new row to the end and returns a builder for that row.

Inherited methods

void checkPosition()

This function throws CursorIndexOutOfBoundsException if the cursor position is out of bounds.

void close()

Closes the Cursor, releasing all of its resources and making it completely invalid.

void copyStringToBuffer(int columnIndex, CharArrayBuffer buffer)

Retrieves the requested column text and stores it in the buffer provided.

void deactivate()

Deactivates the Cursor, making all calls on it fail until requery() is called.

void fillWindow(int position, CursorWindow window)

Copies cursor data into the window.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

byte[] getBlob(int column)

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

int getColumnCount()

Return total number of columns

int getColumnIndex(String columnName)

Returns the zero-based index for the given column name, or -1 if the column doesn't exist.

int getColumnIndexOrThrow(String columnName)

Returns the zero-based index for the given column name, or throws IllegalArgumentException if the column doesn't exist.

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 column)

Returns the value of the requested column as a double.

Bundle getExtras()

Returns a bundle of extra values.

abstract float getFloat(int column)

Returns the value of the requested column as a float.

abstract int getInt(int column)

Returns the value of the requested column as an int.

abstract long getLong(int column)

Returns the value of the requested column as a long.

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).

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).

final int getPosition()

Returns the current position of the cursor in the row set.

abstract short getShort(int column)

Returns the value of the requested column as a short.

abstract String getString(int column)

Returns the value of the requested column as a String.

int getType(int column)

Returns data type of the given column's value.

Object getUpdatedField(int columnIndex)

This method was deprecated in API level 15. Always returns null since Cursors do not support updating rows

boolean getWantsAllOnMoveCalls()

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

CursorWindow getWindow()

If the cursor is backed by a CursorWindow, returns a pre-filled window with the contents of the cursor, otherwise null.

final boolean isAfterLast()

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

final boolean isBeforeFirst()

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

boolean isClosed()

return true if the cursor is closed

boolean isFieldUpdated(int columnIndex)

This method was deprecated in API level 15. Always returns false since Cursors do not support updating rows

final boolean isFirst()

Returns whether the cursor is pointing to the first row.

final boolean isLast()

Returns whether the cursor is pointing to the last row.

abstract boolean isNull(int column)

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

final boolean move(int offset)

Move the cursor by a relative amount, forward or backward, from the current position.

final boolean moveToFirst()

Move the cursor to the first row.

final boolean moveToLast()

Move the cursor to the last row.

final boolean moveToNext()

Move the cursor to the next row.

final boolean moveToPosition(int position)

Move the cursor to an absolute position.

final boolean moveToPrevious()

Move the cursor to the previous row.

void onChange(boolean selfChange)

Subclasses must call this method when they finish committing updates to notify all observers.

boolean onMove(int oldPosition, int newPosition)

This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have.

void registerContentObserver(ContentObserver observer)

Register an observer that is called when changes happen to the content backing this cursor.

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().

boolean requery()

Performs the query that created the cursor again, refreshing its contents.

Bundle respond(Bundle extras)

This is an out-of-band way for the user of a cursor to communicate with the cursor.

void setExtras(Bundle extras)

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

void setNotificationUri(ContentResolver cr, Uri notifyUri)

Specifies a content URI to watch for changes.

void setNotificationUris(ContentResolver cr, List<Uri> notifyUris)

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

void unregisterContentObserver(ContentObserver observer)

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

void unregisterDataSetObserver(DataSetObserver observer)

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

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

abstract void fillWindow(int position, CursorWindow window)

Copies cursor data into the window.

abstract CursorWindow getWindow()

Returns a pre-filled window that contains the data within this cursor.

abstract boolean onMove(int oldPosition, int newPosition)

This function is called every time the cursor is successfully scrolled to a new position, giving the subclass a chance to update any state it may have.

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).

abstract void close()

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

abstract void close()

Closes this resource, relinquishing any underlying resources.

Public constructors

MatrixCursor

Added in API level 1
public MatrixCursor (String[] columnNames)

Constructs a new cursor.

Parameters
columnNames String: names of the columns, the ordering of which determines column ordering elsewhere in this cursor

MatrixCursor

Added in API level 1
public MatrixCursor (String[] columnNames, 
                int initialCapacity)

Constructs a new cursor with the given initial capacity.

Parameters
columnNames String: names of the columns, the ordering of which determines column ordering elsewhere in this cursor

initialCapacity int: in rows

Public methods

addRow

Added in API level 1
public void addRow (Object[] columnValues)

Adds a new row to the end with the given column values. Not safe for concurrent use.

Parameters
columnValues Object: in the same order as the the column names specified at cursor construction time

Throws
IllegalArgumentException if columnValues.length != columnNames.length

addRow

Added in API level 1
public void addRow (Iterable<?> columnValues)

Adds a new row to the end with the given column values. Not safe for concurrent use.

Parameters
columnValues Iterable: in the same order as the the column names specified at cursor construction time

Throws
IllegalArgumentException if columnValues.size() != columnNames.length

getBlob

Added in API level 1
public byte[] getBlob (int column)

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
column 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.

getColumnNames

Added in API level 1
public 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 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 double getDouble (int column)

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

Returns
double the value of that column as a double.

getFloat

Added in API level 1
public float getFloat (int column)

Returns the value of the requested column as a float.

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 float value is implementation-defined.

Parameters
column 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 int getInt (int column)

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
column 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 long getLong (int column)

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

Returns
long the value of that column as a long.

getShort

Added in API level 1
public short getShort (int column)

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
column 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 String getString (int column)

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
column 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 int getType (int column)

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

isNull

Added in API level 1
public boolean isNull (int column)

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

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

Returns
boolean whether the column value is null.

newRow

Added in API level 1
public MatrixCursor.RowBuilder newRow ()

Adds a new row to the end and returns a builder for that row. Not safe for concurrent use.

Returns
MatrixCursor.RowBuilder builder which can be used to set the column values for the new row