io.wcm.handler.media.impl.ImageFileServlet.java Source code

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Here is the source code for io.wcm.handler.media.impl.ImageFileServlet.java

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/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2014 wcm.io
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package io.wcm.handler.media.impl;

import io.wcm.handler.media.CropDimension;
import io.wcm.handler.media.spi.MediaHandlerConfig;
import io.wcm.sling.commons.adapter.AdaptTo;
import io.wcm.wcm.commons.contenttype.ContentType;
import io.wcm.wcm.commons.contenttype.FileExtension;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;
import org.apache.felix.scr.annotations.sling.SlingServlet;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.servlets.HttpConstants;

import com.day.cq.commons.jcr.JcrConstants;
import com.day.image.Layer;

/**
 * Stream resized or cropped image from binary data stored in a nt:file or nt:resource node.
 * Optional support for Content-Disposition header ("download_attachment").
 */
@SlingServlet(resourceTypes = { JcrConstants.NT_FILE,
        JcrConstants.NT_RESOURCE }, selectors = ImageFileServlet.SELECTOR, extensions = MediaFileServlet.EXTENSION, methods = HttpConstants.METHOD_GET)
public final class ImageFileServlet extends AbstractMediaFileServlet {
    private static final long serialVersionUID = 1L;

    /**
     * Selector
     */
    public static final String SELECTOR = "image_file";

    @Override
    protected byte[] getBinaryData(Resource resource, SlingHttpServletRequest request) throws IOException {
        // get media app config
        MediaHandlerConfig config = AdaptTo.notNull(request, MediaHandlerConfig.class);

        // check for image scaling parameters
        int width = 0;
        int height = 0;
        String[] selectors = request.getRequestPathInfo().getSelectors();
        if (selectors.length >= 3) {
            width = NumberUtils.toInt(selectors[1]);
            height = NumberUtils.toInt(selectors[2]);
        }
        if (width <= 0 || height <= 0) {
            return null;
        }

        // check for cropping parameter
        CropDimension cropDimension = null;
        if (selectors.length >= 4) {
            String cropString = selectors[3];
            try {
                cropDimension = CropDimension.fromCropString(cropString);
            } catch (IllegalArgumentException ex) {
                // ignore
            }
        }

        // if resizing requested rescale via layer
        Layer layer = resource.adaptTo(Layer.class);
        if (layer == null) {
            return null;
        }

        // if required: crop image
        if (cropDimension != null) {
            layer.crop(cropDimension.getRectangle());
        }

        // resize layer
        if (width <= layer.getWidth() && height <= layer.getHeight()) {
            layer.resize(width, height);
        }

        // stream to byte array
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        String contentType = getContentType(resource, request);
        layer.write(contentType, config.getDefaultImageQuality(contentType), bos);
        bos.flush();
        return bos.toByteArray();
    }

    @Override
    protected String getContentType(Resource resource, SlingHttpServletRequest request) {

        // get filename from suffix to get extension
        String fileName = request.getRequestPathInfo().getSuffix();
        if (StringUtils.isNotEmpty(fileName)) {
            // if extension is PNG use PNG content type, otherwise fallback to JPEG
            String fileExtension = StringUtils.substringAfterLast(fileName, ".");
            if (StringUtils.equalsIgnoreCase(fileExtension, FileExtension.PNG)) {
                return ContentType.PNG;
            }
        }

        // for rendered images use JPEG mime type as default fallback
        return ContentType.JPEG;
    }

    /**
     * Get image filename to be used for the URL with file extension matching the image format which is produced by this
     * servlet.
     * @param pOriginalFilename Original filename of the image to render.
     * @return Filename to be used for URL.
     */
    public static String getImageFileName(String pOriginalFilename) {
        String namePart = StringUtils.substringBeforeLast(pOriginalFilename, ".");
        String extensionPart = StringUtils.substringAfterLast(pOriginalFilename, ".");

        // use PNG format if original image is PNG, otherwise always use JPEG
        if (StringUtils.equalsIgnoreCase(extensionPart, FileExtension.PNG)) {
            extensionPart = FileExtension.PNG;
        } else {
            extensionPart = FileExtension.JPEG;
        }
        return namePart + "." + extensionPart;
    }

}