001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.examples.parser;
018
019import java.awt.image.*;
020import java.io.*;
021
022import javax.imageio.*;
023
024import org.apache.juneau.marshall.*;
025import org.apache.juneau.marshall.parser.*;
026
027/**
028 * Example parser that converts byte streams to {@link BufferedImage} objects.
029 *
030 * <h5 class='section'>See Also:</h5><ul>
031 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/Marshalling">Marshalling</a>
032 * </ul>
033 */
034public class ImageParser extends InputStreamParser {
035
036   /**
037    * Constructor with default settings (consumes image/png, image/jpeg and image/jpg).
038    */
039   public ImageParser() {
040      super(create().consumes("image/png,image/jpeg,image/jpg"));
041   }
042
043   /**
044    * {@inheritDoc}
045    */
046   @Override /* Parser */
047   @SuppressWarnings({
048      "unchecked" // Type erasure requires cast for image return
049   })
050   public <T> T doRead(ParserSession session, ParserPipe pipe, ClassMeta<T> type) throws IOException, ParseException {
051      try (var is = pipe.getInputStream()) {
052         BufferedImage image;
053         try {
054            image = ImageIO.read(is);
055         } catch (IIOException e) {
056            // Corrupt data that looks like a supported image.  Unchecked decoder failures are already wrapped
057            // as ParseException by ParserSession.readInner, so only IIOException needs handling here.
058            throw new ParseException(session, e, "Unsupported or unreadable image data");
059         }
060         if (image == null)
061            throw new ParseException(session, "Unsupported or unreadable image data");
062         return (T)image;
063      }
064   }
065}