ScalarDataModel (Java EE 5 SDK)

javax.faces.model Class ScalarDataModel

java.lang.Object
  javax.faces.model.DataModel
      javax.faces.model.ScalarDataModel

public class ScalarDataModel

extends DataModel

ScalarDataModel is a convenience implementation of DataModel that wraps an individual Java object.

ScalarDataModel

public ScalarDataModel()

Construct a new ScalarDataModel with no specified wrapped data.

ScalarDataModel

public ScalarDataModel(Object scalar)

Construct a new ScalarDataModel wrapping the specified scalar object.

参数:

scalar - Scalar to be wrapped (if any)

isRowAvailable

public boolean isRowAvailable()

Return true if there is wrappedData available, and the current value of rowIndex is zero. Otherwise, return false.

规范说明:

isRowAvailable in class DataModel

抛出异常:

FacesException - if an error occurs getting the row availability

getRowCount

public int getRowCount()

If there is wrappedData available, return 1. If no wrappedData is available, return -1.

规范说明:

getRowCount in class DataModel

抛出异常:

FacesException - if an error occurs getting the row count

getRowData

public Object getRowData()

If wrapped data is available, return the wrapped data instance. Otherwise, return null.

规范说明:

getRowData in class DataModel

抛出异常:

FacesException - if an error occurs getting the row data

IllegalArgumentException - if now row data is available at the currently specified row index

getRowIndex

public int getRowIndex()

Description copied from class: DataModel

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.

规范说明:

getRowIndex in class DataModel

抛出异常:

FacesException - if an error occurs getting the row index

setRowIndex

public void setRowIndex(int rowIndex)

Description copied from class: DataModel

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.

规范说明:

setRowIndex in class DataModel

参数:

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

抛出异常:

FacesException - if an error occurs setting the row index

IllegalArgumentException - if rowIndex is less than -1

getWrappedData

public Object getWrappedData()

Description copied from class: DataModel

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

规范说明:

getWrappedData in class DataModel

setWrappedData

public void setWrappedData(Object data)

Description copied from class: DataModel

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.

规范说明:

setWrappedData in class DataModel

参数:

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

抛出异常:

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

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