1 /*

     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package javax.activation;

    27 

    28 import java.awt.datatransfer.DataFlavor;

    29 import java.awt.datatransfer.UnsupportedFlavorException;

    30 import java.io.InputStream;

    31 import java.io.IOException;

    32 import java.io.OutputStream;

    33 import javax.activation.DataSource;

    34 

    35 /**

    36  * The DataContentHandler interface is implemented by objects that can

    37  * be used to extend the capabilities of the DataHandler's implementation

    38  * of the Transferable interface. Through <code>DataContentHandlers</code>

    39  * the framework can be extended to convert streams in to objects, and

    40  * to write objects to streams. <p>

    41  *

    42  * Applications don't generally call the methods in DataContentHandlers

    43  * directly. Instead, an application calls the equivalent methods in

    44  * DataHandler. The DataHandler will attempt to find an appropriate

    45  * DataContentHandler that corresponds to its MIME type using the

    46  * current DataContentHandlerFactory. The DataHandler then calls

    47  * through to the methods in the DataContentHandler.

    48  *

    49  * @since 1.6

    50  */

    51 

    52 public interface DataContentHandler {

    53     /**

    54      * Returns an array of DataFlavor objects indicating the flavors the

    55      * data can be provided in. The array should be ordered according to

    56      * preference for providing the data (from most richly descriptive to

    57      * least descriptive).

    58      *

    59      * @return The DataFlavors.

    60      */

    61     public DataFlavor[] getTransferDataFlavors();

    62 

    63     /**

    64      * Returns an object which represents the data to be transferred.

    65      * The class of the object returned is defined by the representation class

    66      * of the flavor.

    67      *

    68      * @param df The DataFlavor representing the requested type.

    69      * @param ds The DataSource representing the data to be converted.

    70      * @return The constructed Object.

    71      * @exception UnsupportedFlavorException    if the handler doesn't

    72      *                                          support the requested flavor

    73      * @exception IOException   if the data can't be accessed

    74      */

    75     public Object getTransferData(DataFlavor df, DataSource ds)

    76                                 throws UnsupportedFlavorException, IOException;

    77 

    78     /**

    79      * Return an object representing the data in its most preferred form.

    80      * Generally this will be the form described by the first DataFlavor

    81      * returned by the <code>getTransferDataFlavors</code> method.

    82      *

    83      * @param ds The DataSource representing the data to be converted.

    84      * @return The constructed Object.

    85      * @exception IOException   if the data can't be accessed

    86      */

    87     public Object getContent(DataSource ds) throws IOException;

    88 

    89     /**

    90      * Convert the object to a byte stream of the specified MIME type

    91      * and write it to the output stream.

    92      *

    93      * @param obj       The object to be converted.

    94      * @param mimeType  The requested MIME type of the resulting byte stream.

    95      * @param os        The output stream into which to write the converted

    96      *                  byte stream.

    97      * @exception IOException   errors writing to the stream

    98      */

    99     public void writeTo(Object obj, String mimeType, OutputStream os)

   100                                                        throws IOException;

   101 }