org.knime.core.data.collection
Class CollectionCellFactory

java.lang.Object
  org.knime.core.data.collection.CollectionCellFactory

public final class CollectionCellFactory
extends Object

Factory class used to create DataCells that contain a collection of DataCells. Also provides convenient methods to determine the type of the elements (the common super type), if no such collection cell is at hand.

Author:

ohl, University of Konstanz

Method Summary

static ListCell	createListCell(Collection<? extends DataCell> coll) Factory method to create a ListCell based on a collection.
static ListCell	createListCell(DataRow row, int[] cols) Creates a new ListCell based on selected cells from a DataRow.
static SetCell	createSetCell(Collection<? extends DataCell> coll) Factory method to create a SetCell that contains a data cell set based on a collection.
static SetCell	createSetCell(DataRow row, int[] cols) Create new SetCell containing a set based on selected cell from a DataRow.
static SparseListCell	createSparseListCell(Collection<? extends DataCell> cells, DataCell defaultElement) Factory method to create a SparseListCell based on a collection.
static SparseListCell	createSparseListCell(DataRow row, int[] cols, DataCell defaultElement) Creates a new ListCell based on selected cells from a DataRow.
static DataType	getElementType(DataTableSpec tableSpec, int[] cols) Determines the super type of the specified columns.
static DataType	getElementType(DataType[] colType) Determines the super type of all types passed.

Methods inherited from class java.lang.Object

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

Method Detail

createListCell

public static ListCell createListCell(Collection<? extends DataCell> coll)

Factory method to create a ListCell based on a collection.

If the underlying collection stems from a DataRow (as read from a any table), consider to use createListCell(DataRow, int[]) in order to minimize cell access.

Parameters:

coll - The underlying collection.

Returns:

The newly created ListCell.

Throws:

NullPointerException - If the argument is null or contains null values.

createListCell

public static ListCell createListCell(DataRow row,
                                      int[] cols)

Creates a new ListCell based on selected cells from a DataRow. Using this method will check if the row is returned by a BufferedDataTable and will handle blobs appropriately.

Parameters:

row - The underlying row

cols - The indices of interest.

Returns:

A newly created ListCell.

Throws:

NullPointerException - If either argument is null.

IndexOutOfBoundsException - If the indices are invalid.

createSparseListCell

public static SparseListCell createSparseListCell(DataRow row,
                                                  int[] cols,
                                                  DataCell defaultElement)

Creates a new ListCell based on selected cells from a DataRow. This method will check if the row is returned by a BufferedDataTable and will handle blobs appropriately. Only the values that are different from the given default value are stored in the sparse list.

Parameters:

row - The underlying row

cols - The indices of interest.

defaultElement - The default element to use.

Returns:

A newly created SparseListCell.

Throws:

NullPointerException - If either argument is null.

IndexOutOfBoundsException - If the indices are invalid.

createSparseListCell

public static SparseListCell createSparseListCell(Collection<? extends DataCell> cells,
                                                  DataCell defaultElement)

Factory method to create a SparseListCell based on a collection. The SparseListCell stores only the values that are different from the default value.

If the underlying collection stems from a DataRow (as read from a any table), consider to use createListCell(DataRow, int[]) in order to minimize cell access.

Parameters:

cells - The underlying collection.

defaultElement - The default element to use.

Returns:

The newly created ListCell.

Throws:

NullPointerException - If the argument is null or contains null values.

createSetCell

public static SetCell createSetCell(Collection<? extends DataCell> coll)

Factory method to create a SetCell that contains a data cell set based on a collection.

If the underlying collection stems from a DataRow (as read from a any table), consider to use createSetCell(DataRow, int[]) in order to minimize cell access.

Parameters:

coll - The underlying collection.

Returns:

The newly created SetCell.

Throws:

NullPointerException - If the argument is null or contains null values.

createSetCell

public static SetCell createSetCell(DataRow row,
                                    int[] cols)

Create new SetCell containing a set based on selected cell from a DataRow. Using this method will check if the row is returned by a BufferedDataTable and will handle blobs appropriately.

Parameters:

row - The underlying row

cols - The indices of cells to be stored in the set.

Returns:

A newly created SetCell.

Throws:

NullPointerException - If either argument is null.

IndexOutOfBoundsException - If the indices are invalid.

getElementType

public static DataType getElementType(DataTableSpec tableSpec,
                                      int[] cols)

Determines the super type of the specified columns. This type will be the element type if a collection is created from the elements in the specified columns.

Parameters:

tableSpec - containing the types of the selected columns

cols - the indices of the columns to determine the common super type of

Returns:

the common super type of the specified columns in the table spec

Throws:

NullPointerException - if either of the arguments is null

ArrayIndexOutOfBoundsException - if the provided column indices are invalid.

getElementType

public static DataType getElementType(DataType[] colType)

Determines the super type of all types passed. This type will be the element type if a collection is created from element of this type.

Parameters:

colType - the types of which the common super type should be returned.

Returns:

the common super type of the specified types

Throws:

NullPointerException - if the array or one of its elements is null