1 /*
   2  * Copyright (c) 2000, 2004, 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 com.sun.imageio.plugins.jpeg;
  27 
  28 import java.util.Locale;
  29 import javax.imageio.spi.ImageReaderSpi;
  30 import javax.imageio.stream.ImageInputStream;
  31 import javax.imageio.spi.IIORegistry;
  32 import javax.imageio.spi.ServiceRegistry;
  33 import java.io.IOException;
  34 import javax.imageio.ImageReader;
  35 import javax.imageio.IIOException;
  36 
  37 public class JPEGImageReaderSpi extends ImageReaderSpi {
  38 
  39     private static String [] writerSpiNames =
  40         {"com.sun.imageio.plugins.jpeg.JPEGImageWriterSpi"};
  41 
  42     public JPEGImageReaderSpi() {
  43         super(JPEG.vendor,
  44               JPEG.version,
  45               JPEG.names,
  46               JPEG.suffixes,
  47               JPEG.MIMETypes,
  48               "com.sun.imageio.plugins.jpeg.JPEGImageReader",
  49               new Class[] { ImageInputStream.class },
  50               writerSpiNames,
  51               true,
  52               JPEG.nativeStreamMetadataFormatName,
  53               JPEG.nativeStreamMetadataFormatClassName,
  54               null, null,
  55               true,
  56               JPEG.nativeImageMetadataFormatName,
  57               JPEG.nativeImageMetadataFormatClassName,
  58               null, null
  59               );
  60     }
  61 
  62     public String getDescription(Locale locale) {
  63         return "Standard JPEG Image Reader";
  64     }
  65 
  66     public boolean canDecodeInput(Object source) throws IOException {
  67         if (!(source instanceof ImageInputStream)) {
  68             return false;
  69         }
  70         ImageInputStream iis = (ImageInputStream) source;
  71         iis.mark();
  72         // If the first two bytes are a JPEG SOI marker, it's probably
  73         // a JPEG file.  If they aren't, it definitely isn't a JPEG file.
  74         int byte1 = iis.read();
  75         int byte2 = iis.read();
  76         iis.reset();
  77         if ((byte1 == 0xFF) && (byte2 == JPEG.SOI)) {
  78             return true;
  79         }
  80         return false;
  81     }
  82 
  83     public ImageReader createReaderInstance(Object extension)
  84         throws IIOException {
  85         return new JPEGImageReader(this);
  86     }
  87 
  88 }