Return all the commands for this type of data.

  Return all the commands for this type of data.
This method returns an array containing all commands
for the type of data represented by this DataHandler. The
MIME type for the underlying data represented by this DataHandler
is used to call through to the getAllCommands method
of the CommandMap associated with this DataHandler.
Returns: the CommandInfo objects representing all the commands
See Also: CommandMap.getAllCommands(java.lang.String),

  A convenience method that takes a CommandInfo object and instantiates the corresponding command, usually a JavaBean component.

  A convenience method that takes a CommandInfo object and instantiates the corresponding command, usually a JavaBean component.

This method calls the CommandInfo's getCommandObject method with the ClassLoader used to load the javax.activation.DataHandler class itself.
Returns: the instantiated command object
Parameters:
- cmdinfo - the CommandInfo corresponding to a command

  Get the command cmdName.

  Get the command cmdName. Use the search semantics as
defined by the CommandMap installed in this DataHandler. The
MIME type for the underlying data represented by this DataHandler
is used to call through to the getCommand method
of the CommandMap associated with this DataHandler.
Returns: the CommandInfo corresponding to the command
Parameters:
- cmdName - the command name
See Also: CommandMap.getCommand(java.lang.String, java.lang.String),

  Return the data in its preferred Object form.

  Return the data in its preferred Object form.

If the DataHandler was instantiated with an object, return the object.

If the DataHandler was instantiated with a DataSource, this method uses a DataContentHandler to return the content object for the data represented by this DataHandler. If no DataContentHandler can be found for the the type of this data, the DataHandler returns an InputStream for the data.
Returns: the content.
Throws:
- IOException - if an IOException occurs during this operation.

  Return the MIME type of this object as retrieved from the source object.

  Return the MIME type of this object as retrieved from
the source object. Note that this is the full
type with parameters.
Returns: the MIME type

  Return the DataSource associated with this instance of DataHandler.

  Return the DataSource associated with this instance of DataHandler.

For DataHandlers that have been instantiated with a DataSource, this method returns the DataSource that was used to create the DataHandler object. In other cases the DataHandler constructs a DataSource from the data used to construct the DataHandler. DataSources created for DataHandlers not instantiated with a DataSource are cached for performance reasons.
Returns: a valid DataSource object for this DataHandler

  Get the InputStream for this object.

  Get the InputStream for this object.

For DataHandlers instantiated with a DataSource, the DataHandler calls the DataSource.getInputStream method and returns the result to the caller.

For DataHandlers instantiated with an Object, the DataHandler first attempts to find a DataContentHandler for the Object. If the DataHandler can not find a DataContentHandler for this MIME type, it throws an UnsupportedDataTypeException. If it is successful, it creates a pipe and a thread. The thread uses the DataContentHandler's writeTo method to write the stream data into one end of the pipe. The other end of the pipe is returned to the caller. Because a thread is created to copy the data, IOExceptions that may occur during the copy can not be propagated back to the caller. The result is an empty stream.

Returns: the InputStream representing this data
Throws:
- IOException - if an I/O error occurs
See Also: DataContentHandler.writeTo(java.lang.Object, java.lang.String, java.io.OutputStream), UnsupportedDataTypeException,

  Return the name of the data object.

  Return the name of the data object. If this DataHandler
was created with a DataSource, this method calls through
to the DataSource.getName method, otherwise it
returns null.
Returns: the name of the object

  Get an OutputStream for this DataHandler to allow overwriting the underlying data.

  Get an OutputStream for this DataHandler to allow overwriting
the underlying data.
If the DataHandler was created with a DataSource, the
DataSource's getOutputStream method is called.
Otherwise, null is returned.
Returns: the OutputStream
See Also: DataSource.getOutputStream(), URLDataSource,

  Return the preferred commands for this type of data.

  Return the preferred commands for this type of data.
This method calls the getPreferredCommands method
in the CommandMap associated with this instance of DataHandler.
This method returns an array that represents a subset of
available commands. In cases where multiple commands for the
MIME type represented by this DataHandler are present, the
installed CommandMap chooses the appropriate commands.
Returns: the CommandInfo objects representing the preferred commands
See Also: CommandMap.getPreferredCommands(java.lang.String),

  Returns an object that represents the data to be transferred.

  Returns an object that represents the data to be transferred. The class of the object returned is defined by the representation class of the data flavor.

For DataHandler's created with DataSources or URLs:

The DataHandler attempts to locate a DataContentHandler for this MIME type. If one is found, the passed in DataFlavor and the type of the data are passed to its getTransferData method. If the DataHandler fails to locate a DataContentHandler and the flavor specifies this object's MIME type and the java.io.InputStream class, this object's InputStream is returned. Otherwise it throws an UnsupportedFlavorException.

For DataHandler's created with Objects:

The DataHandler attempts to locate a DataContentHandler for this MIME type. If one is found, the passed in DataFlavor and the type of the data are passed to its getTransferData method. If the DataHandler fails to locate a DataContentHandler and the flavor specifies this object's MIME type and its class, this DataHandler's referenced object is returned. Otherwise it throws an UnsupportedFlavorException.
Returns: the object
Parameters:
- flavor - the requested flavor for the data
Throws:
- UnsupportedFlavorException - if the data could not be converted to the requested flavor
- IOException - if an I/O error occurs
See Also: ActivationDataFlavor,

  Return the DataFlavors in which this data is available.

  Return the DataFlavors in which this data is available.

Returns an array of DataFlavor objects indicating the flavors the data can be provided in. The array is usually ordered according to preference for providing the data, from most richly descriptive to least richly descriptive.

The DataHandler attempts to find a DataContentHandler that corresponds to the MIME type of the data. If one is located, the DataHandler calls the DataContentHandler's getTransferDataFlavors method.

If a DataContentHandler can not be located, and if the DataHandler was created with a DataSource (or URL), one DataFlavor is returned that represents this object's MIME type and the java.io.InputStream class. If the DataHandler was created with an object and a MIME type, getTransferDataFlavors returns one DataFlavor that represents this object's MIME type and the object's class.
Returns: an array of data flavors in which this data can be transferred
See Also: DataContentHandler.getTransferDataFlavors(),

  Returns whether the specified data flavor is supported for this object.

  Returns whether the specified data flavor is supported for this object.

This method iterates through the DataFlavors returned from getTransferDataFlavors, comparing each with the specified flavor.
Returns: true if the data flavor is supported
Parameters:
- flavor - the requested flavor for the data
See Also: DataHandler.getTransferDataFlavors(),

  Set the CommandMap for use by this DataHandler.

  Set the CommandMap for use by this DataHandler.
Setting it to null causes the CommandMap to revert
to the CommandMap returned by the
CommandMap.getDefaultCommandMap method.
Changing the CommandMap, or setting it to null,
clears out any data cached from the previous CommandMap.
Parameters:
- commandMap - the CommandMap to use in this DataHandler
See Also: CommandMap.setDefaultCommandMap(javax.activation.CommandMap),

  Sets the DataContentHandlerFactory.

  Sets the DataContentHandlerFactory. The DataContentHandlerFactory is called first to find DataContentHandlers. The DataContentHandlerFactory can only be set once.

If the DataContentHandlerFactory has already been set, this method throws an Error.
Parameters:
- newFactory - the DataContentHandlerFactory
Throws:
- Error - if the factory has already been defined.
See Also: DataContentHandlerFactory,

  Write the data to an OutputStream.

  Write the data to an OutputStream.

If the DataHandler was created with a DataSource, writeTo retrieves the InputStream and copies the bytes from the InputStream to the OutputStream passed in.

If the DataHandler was created with an object, writeTo retrieves the DataContentHandler for the object's type. If the DataContentHandler was found, it calls the writeTo method on the DataContentHandler.
Parameters:
- os - the OutputStream to write to
Throws:
- IOException - if an I/O error occurs