Create a DataHandler instance referencing the specified DataSource. The data exists in a byte stream form. The DataSource will provide an InputStream to access the data.

ds	the DataSource

Create a DataHandler instance representing an object of this MIME type. This constructor is used when the application already has an in-memory representation of the data in the form of a Java Object.

obj	the Java Object
mimeType	the MIME type of the object

Create a DataHandler instance referencing a URL. The DataHandler internally creates a URLDataSource instance to represent the URL.

url	a URL object

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.

os	the OutputStream to write to
Throws	IOException: if an I/O error occurs

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.

return	the CommandInfo objects representing all the commands
See also	getAllCommands

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.

cmdinfo	the CommandInfo corresponding to a command
return	the instantiated command object

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.

cmdName	the command name
return	the CommandInfo corresponding to the command
See also	getCommand

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.

commandMap	the CommandMap to use in this DataHandler
See also	setDefaultCommandMap

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.

return	the content.
Throws	IOException: if an IOException occurs during this operation.

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

return

the MIME type

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.

newFactory	the DataContentHandlerFactory
Throws	Error: if the factory has already been defined.
See also	javax.activation.DataContentHandlerFactory

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.

flavor	the requested flavor for the data
return	true if the data flavor is supported
See also	getTransferDataFlavors

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.

return

a valid DataSource object for this DataHandler

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.

return	the InputStream representing this data
Throws	IOException: if an I/O error occurs
See also	writeTo, javax.activation.UnsupportedDataTypeException

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.

return

the name of the object

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.

return	the OutputStream
See also	getOutputStream, javax.activation.URLDataSource

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.

return	the CommandInfo objects representing the preferred commands
See also	getPreferredCommands

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.

flavor	the requested flavor for the data
return	the object
Throws	UnsupportedFlavorException: if the data could not be converted to the requested flavor
Throws	IOException: if an I/O error occurs
See also	javax.activation.ActivationDataFlavor

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.

return	an array of data flavors in which this data can be transferred
See also	getTransferDataFlavors