Class DataRowLayout

java.lang.Object

org.apache.cayenne.DataRowLayout

All Implemented Interfaces:

Serializable

public final class DataRowLayout
extends Object
implements Serializable

The layout of a DataRow: the column names in column order, with a lookup of a name to its position. A row holds its values by position in its layout, and all the rows of one result set share a layout. Layouts are immutable and compared by identity, so two rows share a layout only when they came from the same reader. A layout is serializable, and the rows serialized in one stream keep sharing theirs.

A consumer that needs a fixed set of columns from rows of any layouts builds a layout of those names and reads them through a DataRowLayout.Reader of it.

Since:

5.0

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	DataRowLayout.Reader	Reads the columns of a layout from rows of any layouts.

Method Summary

Modifier and Type	Method	Description
int	indexOf(String name)	Returns the position of the named column, or -1 if there is no such column.
String	nameAt(int index)	Returns the name of the column at the given position.
static DataRowLayout	of(String... names)	Returns a layout of the given column names, in the given order.
DataRowLayout.Reader	reader()	Returns a reader of the columns of this layout from rows of any layouts.
int	size()	Returns the number of columns.
String	toString()

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

of

public static DataRowLayout of(String... names)

Returns a layout of the given column names, in the given order. A repeated name is deduplicated: the last occurrence keeps the name, the way the last put wins in a map, and each earlier one is renamed with an underscore appended until it is unique.

size

public int size()

Returns the number of columns.

indexOf

public int indexOf(String name)

Returns the position of the named column, or -1 if there is no such column.

nameAt

public String nameAt(int index)

Returns the name of the column at the given position.

reader

public DataRowLayout.Reader reader()

Returns a reader of the columns of this layout from rows of any layouts.

toString

public String toString()

Overrides:

toString in class Object