com.sun.data.provider.impl
Class AbstractDataProvider

java.lang.Object
  com.sun.data.provider.impl.AbstractDataProvider

All Implemented Interfaces:

DataProvider, java.io.Serializable

Direct Known Subclasses:

AbstractTableDataProvider, BasicTransactionalDataProvider, MapDataProvider, ObjectDataProvider, TableRowDataProvider

public abstract class AbstractDataProvider

extends java.lang.Object

implements DataProvider, java.io.Serializable

Abstract base implementation of DataProvider. This class is a convenient base class to use when creating a new DataProvider implementation.

Author:

Joe Nuxoll

See Also:

Serialized Form

Field Summary

protected DataListener[]	dpListeners Array of DataListener instances registered for this DataProvider.
protected FieldKey[]	fieldKeys storage for the list of FieldKeys in this DataProvider

Constructor Summary

AbstractDataProvider()

Method Summary

void	addDataListener(DataListener listener) Register a new DataListener to this DataProvider instance.
protected void	addFieldKey(FieldKey fieldKey) Adds a FieldKey to the list of keys
protected void	addFieldKeys(FieldKey[] fieldKeys) Adds a list of FieldKeys to the list of keys
protected void	clearFieldKeys() Empties the list of FieldKeys
protected void	fireProviderChanged() Fires a providerChanged event to each registered DataListener
protected void	fireValueChanged(FieldKey fieldKey, java.lang.Object oldValue, java.lang.Object newValue) Fires a valueChanged event to each registered DataListener
DataListener[]	getDataListeners()
static java.lang.Object	getFakeData(java.lang.Class dataType) This helper method defers to getFakeData(Class, Class) passing null as the collectionElementType.
static java.lang.Object	getFakeData(java.lang.Class dataType, java.lang.Class collectionElementType) This helper method produces fake data for use during design-time.
FieldKey	getFieldKey(java.lang.String fieldId) Returns the FieldKey associated with the specified data element canonical id, if any; otherwise, return null.
FieldKey[]	getFieldKeys()
abstract java.lang.Class	getType(FieldKey fieldKey) Returns the data type of the data element referenced by the specified data key.
java.lang.Class	getType(java.lang.String fieldId)
abstract java.lang.Object	getValue(FieldKey fieldKey) Returns value of the data element referenced by the specified FieldKey.
java.lang.Object	getValue(java.lang.String fieldId)
abstract boolean	isReadOnly(FieldKey fieldKey) Return a flag indicating whether the value of the data element represented by the specified FieldKey can be modified via the setValue() method.
boolean	isReadOnly(java.lang.String fieldId)
void	removeDataListener(DataListener listener) Deregister an existing DataListener from this DataProvider instance.
protected void	removeFieldKey(FieldKey fieldKey) Removes a FieldKey from the list of keys
protected void	removeFieldKeys(FieldKey[] fieldKeys) Removes an array of FieldKeys from the list
abstract void	setValue(FieldKey fieldKey, java.lang.Object value) Set the value of the data element represented by the specified FieldKey to the specified new value.
void	setValue(java.lang.String fieldId, java.lang.Object value)
protected void	sortFieldKeys() Sorts the FieldKeys (using Arrays.sort)

Methods inherited from class java.lang.Object

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

Field Detail

fieldKeys

protected FieldKey[] fieldKeys

storage for the list of FieldKeys in this DataProvider

dpListeners

protected DataListener[] dpListeners

Array of DataListener instances registered for this DataProvider.

Constructor Detail

AbstractDataProvider

public AbstractDataProvider()

Method Detail

getType

public abstract java.lang.Class getType(FieldKey fieldKey)
                                 throws DataProviderException

Returns the data type of the data element referenced by the specified data key.

Specified by:

getType in interface DataProvider

Parameters:

fieldKey - FieldKey identifying the data element whose type is to be returned

Returns:

the data type of the data element referenced by the specified data key

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning null. A DPE may also indicate that the passed fieldKey is not valid. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

isReadOnly

public abstract boolean isReadOnly(FieldKey fieldKey)
                            throws DataProviderException

Return a flag indicating whether the value of the data element represented by the specified FieldKey can be modified via the setValue() method.

Specified by:

isReadOnly in interface DataProvider

Parameters:

fieldKey - FieldKey identifying the data element whose settable status is to be returned

Returns:

a flag indicating whether the value of the data element represented by the specified FieldKey can be modified via the setValue() method

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning true. A DPE may also indicate that the passed fieldKey is not valid. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

getValue

public abstract java.lang.Object getValue(FieldKey fieldKey)
                                   throws DataProviderException

Returns value of the data element referenced by the specified FieldKey.

Specified by:

getValue in interface DataProvider

Parameters:

fieldKey - FieldKey identifying the data element whose value is to be returned

Returns:

value of the data element referenced by the specified FieldKey

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning null. A DPE may also indicate that the passed fieldKey is not valid. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

setValue

public abstract void setValue(FieldKey fieldKey,
                              java.lang.Object value)
                       throws DataProviderException

Set the value of the data element represented by the specified FieldKey to the specified new value.

Specified by:

setValue in interface DataProvider

Parameters:

fieldKey - FieldKey identifying the data element whose value is to be modified

value - New value for this data element

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning null. A DPE may also indicate that the passed fieldKey is not valid. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

getType

public java.lang.Class getType(java.lang.String fieldId)
                        throws DataProviderException

Throws:

DataProviderException

isReadOnly

public boolean isReadOnly(java.lang.String fieldId)
                   throws DataProviderException

Throws:

DataProviderException

getValue

public java.lang.Object getValue(java.lang.String fieldId)
                          throws DataProviderException

Throws:

DataProviderException

setValue

public void setValue(java.lang.String fieldId,
                     java.lang.Object value)
              throws DataProviderException

Throws:

DataProviderException

addFieldKey

protected void addFieldKey(FieldKey fieldKey)

Adds a FieldKey to the list of keys

Parameters:

fieldKey - FieldKey to add to the list of keys

addFieldKeys

protected void addFieldKeys(FieldKey[] fieldKeys)

Adds a list of FieldKeys to the list of keys

Parameters:

fieldKeys - FieldKey[] to add to the list of keys

sortFieldKeys

protected void sortFieldKeys()

Sorts the FieldKeys (using Arrays.sort)

removeFieldKey

protected void removeFieldKey(FieldKey fieldKey)

Removes a FieldKey from the list of keys

Parameters:

fieldKey - FieldKey to remove from the list

removeFieldKeys

protected void removeFieldKeys(FieldKey[] fieldKeys)

Removes an array of FieldKeys from the list

Parameters:

fieldKeys - FieldKey[] to remove from the list

clearFieldKeys

protected void clearFieldKeys()

Empties the list of FieldKeys

getFieldKeys

public FieldKey[] getFieldKeys()
                        throws DataProviderException

Specified by:

getFieldKeys in interface DataProvider

Returns:

An array of all FieldKeys supported by this DataProvider. If the set of valid FieldKeys cannot be determined, return null instead.

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning null or an empty array. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

getFieldKey

public FieldKey getFieldKey(java.lang.String fieldId)
                     throws DataProviderException

Returns the FieldKey associated with the specified data element canonical id, if any; otherwise, return null.

Specified by:

getFieldKey in interface DataProvider

Parameters:

fieldId - Canonical id of the requested FieldKey

Returns:

the FieldKey associated with the specified data element canonical id, if any; otherwise, return null

Throws:

DataProviderException - Implementations may wish to surface internal exceptions (nested in DataProviderException) rather than simply returning null. A DPE may also indicate that the passed fieldId is not valid. Consult the documentation of the specific DataProvider implementation for details on what exceptions might be wrapped by a DPE.

getFakeData

public static java.lang.Object getFakeData(java.lang.Class dataType)

This helper method defers to getFakeData(Class, Class) passing null as the collectionElementType. This is used for design-time only rendering of fake data.

Parameters:

dataType - The Class representing the type of data to fake

Returns:

The fake data object

getFakeData

public static java.lang.Object getFakeData(java.lang.Class dataType,
                                           java.lang.Class collectionElementType)

This helper method produces fake data for use during design-time. This allows a DataProvider implementation class to avoid a costly call to a database, web service, or EJB method at design-time. This will handle array and collection types as well as object types.

If the underlying type is other than a primitive type or java.lang common type, it is constructed by attempting to use the default constructor for the class, if it exists. The method will then recurse to populate the properties and fields of the nested object (avoiding recursion). If no default constructor exists, this method will return null for the value.

Parameters:

dataType - The Class representing the type of data to fake. This might be a native array, Collection, or any Object subtype

collectionElementType - If the 'dataType' is a Collection type, this parameter specifies the type of element stored in the Collection

Returns:

The fake data object

addDataListener

public void addDataListener(DataListener listener)

Register a new DataListener to this DataProvider instance.

Specified by:

addDataListener in interface DataProvider

Parameters:

listener - New DataListener to register

removeDataListener

public void removeDataListener(DataListener listener)

Deregister an existing DataListener from this DataProvider instance.

Specified by:

removeDataListener in interface DataProvider

Parameters:

listener - Old DataListener to deregister

getDataListeners

public DataListener[] getDataListeners()

Specified by:

getDataListeners in interface DataProvider

Returns:

An array of the DataListeners currently registered on this DataProvider. If there are no registered listeners, a zero-length array is returned.

fireValueChanged

protected void fireValueChanged(FieldKey fieldKey,
                                java.lang.Object oldValue,
                                java.lang.Object newValue)

Fires a valueChanged event to each registered DataListener

Parameters:

fieldKey - FieldKey identifying the changed value

oldValue - The old value (before the change)

newValue - The new value (after the change)

See Also:

DataListener.valueChanged(DataProvider, FieldKey, Object, Object)

fireProviderChanged

protected void fireProviderChanged()

Fires a providerChanged event to each registered DataListener

See Also:

DataListener.providerChanged(DataProvider)