com.lumata.lib.lupa.internal.ImageServiceImpl.java Source code

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Here is the source code for com.lumata.lib.lupa.internal.ImageServiceImpl.java

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/**
 * Copyright (c) 2013 Lumata
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.lumata.lib.lupa.internal;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

import com.google.common.net.MediaType;
import com.lumata.lib.lupa.HttpService;
import com.lumata.lib.lupa.ImageService;
import com.lumata.lib.lupa.ReadableResource;
import com.lumata.lib.lupa.content.Image;

/**
 * @author Alexander De Leon - alexander.leon@lumatagroup.com
 * 
 */
public class ImageServiceImpl implements ImageService {

    private final HttpService httpService;

    public ImageServiceImpl(HttpService httpService) {
        super();
        this.httpService = httpService;
    }

    @Override
    public Image getImageFromUrl(URL imageUrl) throws IOException {
        ReadableResource resource = httpService.getRawResource(imageUrl);
        return getImageFromResource(resource);

    }

    @Override
    public Image getImageFromResource(ReadableResource resource) throws IOException {
        // read before checking content type to avoid doing an HTTP HEAD.
        InputStream imageStream = resource.read();

        // check that the URL returns something that appears that is expected to
        // be an image.
        if (!isImageMimeType(resource)) {
            return null;
        }

        Image imageMetadata = new Image(resource.getUrl().toExternalForm());
        populateImageDimensions(imageStream, imageMetadata);

        resource.discard();
        return imageMetadata;
    }

    /*------------------ helper methods --- */
    /**
     * @param resource
     * @param imageMetadata
     * @throws IOException
     */
    private void populateImageDimensions(InputStream stream, Image imageMetadata) throws IOException {
        ImageInputStream imageStream = ImageIO.createImageInputStream(stream);
        try {
            final Iterator<ImageReader> readers = ImageIO.getImageReaders(imageStream);
            if (readers.hasNext()) {
                ImageReader reader = readers.next();
                try {
                    reader.setInput(imageStream);
                    imageMetadata.setWidth(reader.getWidth(0));
                    imageMetadata.setHeight(reader.getHeight(0));
                } finally {
                    reader.dispose();
                }
            }
        } finally {
            if (imageStream != null) {
                imageStream.close();
            }
        }
    }

    /**
     * @param contentType
     * @return
     */
    private boolean isImageMimeType(ReadableResource readableResource) {
        if (!readableResource.getContentType().isPresent()) {
            return false;
        }
        return readableResource.getContentType().get().is(MediaType.ANY_IMAGE_TYPE);
    }
}