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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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package javax.activation;

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.activation.DataSource;


The DataContentHandler interface is implemented by objects that can
be used to extend the capabilities of the DataHandler's implementation
of the Transferable interface. Through DataContentHandlers
the framework can be extended to convert streams in to objects, and
to write objects to streams.


An implementation of DataContentHandler should be a public class with a public no-arg constructor. If the implementation class is in a named module then it should be in an API package that is exported to the module java.activation.


Applications don't generally call the methods in DataContentHandlers
directly. Instead, an application calls the equivalent methods in
DataHandler. The DataHandler will attempt to find an appropriate
DataContentHandler that corresponds to its MIME type using the
current DataContentHandlerFactory. The DataHandler then calls
through to the methods in the DataContentHandler.


Since:1.6
/**
 * <p>The DataContentHandler interface is implemented by objects that can
 * be used to extend the capabilities of the DataHandler's implementation
 * of the Transferable interface. Through <code>DataContentHandlers</code>
 * the framework can be extended to convert streams in to objects, and
 * to write objects to streams.</p>
 *
 * <p>An implementation of DataContentHandler should be a public class
 * with a public no-arg constructor. If the implementation class is in
 * a named module then it should be in an API package that is exported
 * to the module {@code java.activation}.</p>
 *
 * <p>Applications don't generally call the methods in DataContentHandlers
 * directly. Instead, an application calls the equivalent methods in
 * DataHandler. The DataHandler will attempt to find an appropriate
 * DataContentHandler that corresponds to its MIME type using the
 * current DataContentHandlerFactory. The DataHandler then calls
 * through to the methods in the DataContentHandler.</p>
 *
 * @since 1.6
 */

public interface DataContentHandler {
    
Returns an array of DataFlavor objects indicating the flavors the
data can be provided in. The array should be ordered according to
preference for providing the data (from most richly descriptive to
least descriptive).

Returns:The DataFlavors.
/**
     * Returns an array of DataFlavor objects indicating the flavors the
     * data can be provided in. The array should be ordered according to
     * preference for providing the data (from most richly descriptive to
     * least descriptive).
     *
     * @return The DataFlavors.
     */
    public DataFlavor[] getTransferDataFlavors();

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

Params:
  • df – The DataFlavor representing the requested type.
  • ds – The DataSource representing the data to be converted.
Throws:
Returns:The constructed Object.
/**
     * Returns an object which represents the data to be transferred.
     * The class of the object returned is defined by the representation class
     * of the flavor.
     *
     * @param df The DataFlavor representing the requested type.
     * @param ds The DataSource representing the data to be converted.
     * @return The constructed Object.
     * @exception UnsupportedFlavorException    if the handler doesn't
     *                                          support the requested flavor
     * @exception IOException   if the data can't be accessed
     */
    public Object getTransferData(DataFlavor df, DataSource ds)
                                throws UnsupportedFlavorException, IOException;

    
Return an object representing the data in its most preferred form.
Generally this will be the form described by the first DataFlavor
returned by the getTransferDataFlavors method.

Params:
  • ds – The DataSource representing the data to be converted.
Throws:
Returns:The constructed Object.
/**
     * Return an object representing the data in its most preferred form.
     * Generally this will be the form described by the first DataFlavor
     * returned by the <code>getTransferDataFlavors</code> method.
     *
     * @param ds The DataSource representing the data to be converted.
     * @return The constructed Object.
     * @exception IOException   if the data can't be accessed
     */
    public Object getContent(DataSource ds) throws IOException;

    
Convert the object to a byte stream of the specified MIME type
and write it to the output stream.

Params:
  • obj –       The object to be converted.
  • mimeType –  The requested MIME type of the resulting byte stream.
  • os –        The output stream into which to write the converted
                 byte stream.
Throws:
/**
     * Convert the object to a byte stream of the specified MIME type
     * and write it to the output stream.
     *
     * @param obj       The object to be converted.
     * @param mimeType  The requested MIME type of the resulting byte stream.
     * @param os        The output stream into which to write the converted
     *                  byte stream.
     * @exception IOException   errors writing to the stream
     */
    public void writeTo(Object obj, String mimeType, OutputStream os)
                                                       throws IOException;
}