001/*
002 *  Copyright 2013 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.core.util;
017
018import java.io.ByteArrayOutputStream;
019import java.io.IOException;
020import java.io.InputStream;
021
022import org.apache.commons.codec.binary.Base64;
023import org.apache.commons.lang3.StringUtils;
024
025/**
026 * Class providing helper methods to resolve images.
027 */
028public final class ImageResolverHelper
029{
030    
031    private ImageResolverHelper()
032    {
033        // Hides the default constructor.
034    }
035
036    /**
037     * Get an image's bytes encoded as base64, optionally resized.
038     * @param dataIs an input stream on the image bytes.
039     * @param mimeType the image mime type.
040     * @param height the specified height. Ignored if negative.
041     * @param width the specified width. Ignored if negative.
042     * @param maxHeight the maximum image height. Ignored if height or width is specified.
043     * @param maxWidth the maximum image width. Ignored if height or width is specified.
044     * @return the image bytes encoded as base64.
045     * @throws IOException if an error occurs.
046     */
047    
048    public static final String resolveImageAsBase64(InputStream dataIs, String mimeType, int height, int width, int maxHeight, int maxWidth) throws IOException
049    {
050        return resolveImageAsBase64(dataIs, mimeType, height, width, maxHeight, maxWidth, 0, 0);
051    }
052    
053    /**
054     * Get an image's bytes encoded as base64, optionally resized.
055     * @param dataIs an input stream on the image bytes.
056     * @param mimeType the image mime type.
057     * @param height the specified height. Ignored if 0.
058     * @param width the specified width. Ignored if 0.
059     * @param maxHeight the maximum image height. Ignored if height or width is specified.
060     * @param maxWidth the maximum image width. Ignored if height or width is specified.
061     * @param cropHeight the cropping height. Ignored if 0.
062     * @param cropWidth the cropping width. Ignored if 0.
063     * @return the image bytes encoded as base64.
064     * @throws IOException if an error occurs.
065     */
066    public static final String resolveImageAsBase64(InputStream dataIs, String mimeType, int height, int width, int maxHeight, int maxWidth, int cropHeight, int cropWidth) throws IOException
067    {
068        if (!StringUtils.startsWith(mimeType, "image/"))
069        {
070            return "";
071        }
072        
073        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
074        
075        String format = StringUtils.substringAfter(mimeType, "/");
076        ImageHelper.generateThumbnail(dataIs, buffer, format, height, width, maxHeight, maxWidth, cropHeight, cropWidth);
077        
078        String data = Base64.encodeBase64String(buffer.toByteArray());
079        
080        return "data:" + mimeType + ";base64," + data;
081    }
082}