DataModel is an abstraction around arbitrary data binding technologies that can be used to adapt a variety of data sources for use by Jakarta Faces components that support per-row processing for their child components (such as UIData.

The data collection underlying a DataModel instance is modeled as a collection of row objects that can be accessed by a zero-relative cursor (row index). The APIs provide mechanisms to position to a specified zero-relative row index, and to retrieve an object that represents the data that corresponds to the current row index.

A concrete DataModel instance is attached to a particular collection of underlying data by calling the setWrappedData() method. It can be detached from that underlying data collection by passing a null parameter to this method.

Concrete DataModel implementations must provide a public zero-arguments constructor that calls setWrappedData(null). A convenience constructor that takes a wrapped object of the appropriate type (and passes it on via a call to setWrappedData(), should also be provided.

Event listeners may be registered to receive notifications of when a new row index is selected.

Modifier and Type	Class and Description
private static class	DataModel.DataModelIterator<T>

Modifier and Type	Field and Description
private static final DataModelListener[]	EMPTY_DATA_MODEL_LISTENER
private List<DataModelListener>	listeners The list of registered `DataModelListener`s for this `DataModel`.

Constructor Summary

Access	Constructor and Description
public	DataModel()

Method Summary

Modifier and Type	Method and Description
public void	addDataModelListener(DataModelListener The new `DataModelListener` to be registered listener) Add a new `DataModelListener` to the set interested in notifications from this `DataModel`.
public DataModelListener[]	Returns: the listeners for this instance, or an empty array getDataModelListeners() Return the set of `DataModelListener`s interested in notifications from this `DataModel`.
public abstract int	Returns: the number of rows of data represented by this `DataModel` getRowCount() Return the number of rows of data objects represented by this `DataModel`.
public abstract E	Returns: an object representing the data for the currently selected row index getRowData() Return an object representing the data for the currently selected row index.
public abstract int	Returns: the index of the currently selected row getRowIndex() Return the zero-relative index of the currently selected row.
public abstract Object	Returns: the `Object` that this model wraps. getWrappedData() Return the object representing the data wrapped by this `DataModel`, if any.
public abstract boolean	Returns: true if and only if there is data available at the current index, false otherwise. isRowAvailable() Return a flag indicating whether there is `rowData` available at the current `rowIndex`.
public Iterator<E>	iterator() Implements java.lang.Iterable.iterator. Return a read-only `Iterator` over the row data for this model.
public void	removeDataModelListener(DataModelListener The old `DataModelListener` to be deregistered listener) Remove an existing `DataModelListener` from the set interested in notifications from this `DataModel`.
public abstract void	setRowIndex(int The new zero-relative index (must be non-negative) rowIndex) Set the zero-relative index of the currently selected row, or -1 to indicate that we are not positioned on a row.
public abstract void	setWrappedData(Object Data collection to be wrapped, or `null` to detach from any previous data collection data) Set the object representing the data collection wrapped by this `DataModel`.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

EMPTY_DATA_MODEL_LISTENER	back to summary
private static final DataModelListener[] EMPTY_DATA_MODEL_LISTENER

listeners	back to summary
private List<DataModelListener> listeners The list of registered `DataModelListener`s for this `DataModel`. This variable will be `null` unless there is at least one registered listener.

Constructor Detail

DataModel	back to summary
public DataModel()

Method Detail

addDataModelListener back to summary

addDataModelListener	back to summary
public void addDataModelListener(DataModelListener listener) Add a new `DataModelListener` to the set interested in notifications from this `DataModel`. Parameters listener:DataModelListener The new `DataModelListener` to be registered Exceptions NullPointerException: if `listener` is `null`

public void addDataModelListener(DataModelListener listener)

Add a new DataModelListener to the set interested in notifications from this DataModel.

Parameters

listener:DataModelListener: The new DataModelListener to be registered

Exceptions

NullPointerException:: if listener is null

getDataModelListeners back to summary

getDataModelListeners	back to summary
public DataModelListener[] getDataModelListeners() Return the set of `DataModelListener`s interested in notifications from this `DataModel`. If there are no such listeners, an empty array is returned. Returns:DataModelListener[] the listeners for this instance, or an empty array

public DataModelListener[] getDataModelListeners()

Return the set of DataModelListeners interested in notifications from this DataModel. If there are no such listeners, an empty array is returned.

Returns:DataModelListener[]: the listeners for this instance, or an empty array

getRowCount back to summary

getRowCount	back to summary
public abstract int getRowCount() Return the number of rows of data objects represented by this `DataModel`. If the number of rows is unknown, or no `wrappedData` is available, return -1. Returns:int the number of rows of data represented by this `DataModel` Exceptions FacesException: if an error occurs getting the row count

public abstract int getRowCount()

Return the number of rows of data objects represented by this DataModel. If the number of rows is unknown, or no wrappedData is available, return -1.

Returns:int

the number of rows of data represented by this DataModel

Exceptions

FacesException:: if an error occurs getting the row count

getRowData back to summary

getRowData	back to summary
public abstract E getRowData() Return an object representing the data for the currently selected row index. If no `wrappedData` is available, return `null`. Returns:E an object representing the data for the currently selected row index Exceptions FacesException: if an error occurs getting the row data IllegalArgumentException: if now row data is available at the currently specified row index

public abstract E getRowData()

Return an object representing the data for the currently selected row index. If no wrappedData is available, return null.

Returns:E

an object representing the data for the currently selected row index

Exceptions

FacesException:: if an error occurs getting the row data
IllegalArgumentException:: if now row data is available at the currently specified row index

getRowIndex back to summary

getRowIndex	back to summary
public abstract int getRowIndex() Return the zero-relative index of the currently selected row. If we are not currently positioned on a row, or no `wrappedData` is available, return -1. Returns:int the index of the currently selected row Exceptions FacesException: if an error occurs getting the row index

public abstract int getRowIndex()

Return the zero-relative index of the currently selected row. If we are not currently positioned on a row, or no wrappedData is available, return -1.

Returns:int

the index of the currently selected row

Exceptions

FacesException:: if an error occurs getting the row index

getWrappedData back to summary

getWrappedData	back to summary
public abstract Object getWrappedData() Return the object representing the data wrapped by this `DataModel`, if any. Returns:Object the `Object` that this model wraps.

public abstract Object getWrappedData()

Return the object representing the data wrapped by this DataModel, if any.

Returns:Object: the Object that this model wraps.

isRowAvailable back to summary

isRowAvailable	back to summary
public abstract boolean isRowAvailable() Return a flag indicating whether there is `rowData` available at the current `rowIndex`. If no `wrappedData` is available, return `false`. Returns:boolean true if and only if there is data available at the current index, false otherwise. Exceptions FacesException: if an error occurs getting the row availability

public abstract boolean isRowAvailable()

Return a flag indicating whether there is rowData available at the current rowIndex. If no wrappedData is available, return false.

Returns:boolean

true if and only if there is data available at the current index, false otherwise.

Exceptions

FacesException:: if an error occurs getting the row availability

iterator back to summary

iterator	back to summary
public Iterator<E> iterator() Implements java.lang.Iterable.iterator. Return a read-only `Iterator` over the row data for this model. Returns:Iterator<E> Doc from java.lang.Iterable.iterator. an Iterator. Annotations @Override Since 2.0

public Iterator<E> iterator()

Implements java.lang.Iterable.iterator.

Return a read-only Iterator over the row data for this model.

Returns:Iterator<E>

Doc from java.lang.Iterable.iterator.

an Iterator.

Annotations

@Override

Since

2.0

removeDataModelListener back to summary

removeDataModelListener	back to summary
public void removeDataModelListener(DataModelListener listener) Remove an existing `DataModelListener` from the set interested in notifications from this `DataModel`. Parameters listener:DataModelListener The old `DataModelListener` to be deregistered Exceptions NullPointerException: if `listener` is `null`

public void removeDataModelListener(DataModelListener listener)

Remove an existing DataModelListener from the set interested in notifications from this DataModel.

Parameters

listener:DataModelListener: The old DataModelListener to be deregistered

Exceptions

NullPointerException:: if listener is null

setRowIndex back to summary

setRowIndex	back to summary
public abstract void setRowIndex(int rowIndex) Set the zero-relative index of the currently selected row, or -1 to indicate that we are not positioned on a row. It is possible to set the row index at a value for which the underlying data collection does not contain any row data. Therefore, callers may use the `isRowAvailable()` method to detect whether row data will be available for use by the `getRowData()` method. If there is no `wrappedData` available when this method is called, the specified `rowIndex` is stored (and may be retrieved by a subsequent call to `getRowData()`), but no event is sent. Otherwise, if the currently selected row index is changed by this call, a `DataModelEvent` will be sent to the `rowSelected()` method of all registered `DataModelListener`s. Parameters rowIndex:int The new zero-relative index (must be non-negative) Exceptions FacesException: if an error occurs setting the row index IllegalArgumentException: if `rowIndex` is less than -1

public abstract void setRowIndex(int rowIndex)

Set the zero-relative index of the currently selected row, or -1 to indicate that we are not positioned on a row. It is possible to set the row index at a value for which the underlying data collection does not contain any row data. Therefore, callers may use the isRowAvailable() method to detect whether row data will be available for use by the getRowData() method.

If there is no wrappedData available when this method is called, the specified rowIndex is stored (and may be retrieved by a subsequent call to getRowData()), but no event is sent. Otherwise, if the currently selected row index is changed by this call, a DataModelEvent will be sent to the rowSelected() method of all registered DataModelListeners.

Parameters

rowIndex:int: The new zero-relative index (must be non-negative)

Exceptions

FacesException:: if an error occurs setting the row index
IllegalArgumentException:: if rowIndex is less than -1

setWrappedData back to summary

setWrappedData	back to summary
public abstract void setWrappedData(Object data) Set the object representing the data collection wrapped by this `DataModel`. If the specified `data` is `null`, detach this `DataModel` from any previously wrapped data collection instead. If `data` is non-`null`, the currently selected row index must be set to zero, and a `DataModelEvent` must be sent to the `rowSelected()` method of all registered `DataModelListener`s indicating that this row is now selected. Parameters data:Object Data collection to be wrapped, or `null` to detach from any previous data collection Exceptions ClassCastException: if `data` is not of the appropriate type for this `DataModel` implementation

public abstract void setWrappedData(Object data)

Set the object representing the data collection wrapped by this DataModel. If the specified data is null, detach this DataModel from any previously wrapped data collection instead.

If data is non-null, the currently selected row index must be set to zero, and a DataModelEvent must be sent to the rowSelected() method of all registered DataModelListeners indicating that this row is now selected.

Parameters

data:Object: Data collection to be wrapped, or null to detach from any previous data collection

Exceptions

ClassCastException:: if data is not of the appropriate type for this DataModel implementation

jakarta.faces.model back to summary

private final Class DataModel.DataModelIterator<T>

Class Inheritance

extends Object
implements Iterator<T>

java.lang.Object
jakarta.faces.model.DataModel.DataModelIterator

All Implemented Interfaces

java.util.Iterator

Annotations

@SuppressWarnings:unchecked

Field Summary

Modifier and Type	Field and Description
private int	index
private final DataModel<T>	model

Constructor Summary

Access	Constructor and Description
pack-priv	DataModelIterator(DataModel<T> model)

Method Summary

Modifier and Type	Method and Description
public boolean	hasNext() Implements java.util.Iterator.hasNext. Returns `true` if the iteration has more elements.
public T	next() Implements java.util.Iterator.next. Returns the next element in the iteration.
public void	remove() Overrides default java.util.Iterator.remove. Unsupported.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

index	back to summary
private int index

model	back to summary
private final DataModel<T> model

Constructor Detail

DataModelIterator	back to summary
pack-priv DataModelIterator(DataModel<T> model)

Method Detail

hasNext back to summary

hasNext	back to summary
public boolean hasNext() Implements java.util.Iterator.hasNext. Doc from java.util.Iterator.hasNext. Returns `true` if the iteration has more elements. (In other words, returns `true` if `next` would return an element rather than throwing an exception.) Returns:boolean `true` if the iteration has more elements Annotations @Override See Also `java.util.Iterator#hasNext()`

public boolean hasNext()

Implements java.util.Iterator.hasNext.

Doc from java.util.Iterator.hasNext.

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Returns:boolean

true if the iteration has more elements

Annotations

@Override

See Also

java.util.Iterator#hasNext()

next back to summary

next	back to summary
public T next() Implements java.util.Iterator.next. Doc from java.util.Iterator.next. Returns the next element in the iteration. Returns:T the next element in the iteration Annotations @Override See Also `java.util.Iterator#next()`

public T next()

Implements java.util.Iterator.next.

Doc from java.util.Iterator.next.

Returns the next element in the iteration.

Returns:T

the next element in the iteration

Annotations