PictureResource.java

/**
 * Copyright 2011 the original author or authors.
 *
 * 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.
 */
package org.bricket.plugin.picture.web;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Locale;

import org.apache.commons.io.IOUtils;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.ResourceReference;
import org.apache.wicket.injection.web.InjectorHolder;
import org.apache.wicket.markup.html.DynamicWebResource;
import org.apache.wicket.spring.injection.annot.SpringBean;
import org.apache.wicket.util.time.Time;
import org.apache.wicket.util.value.ValueMap;
import org.bricket.plugin.picture.service.PictureModificationService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The static Url methods are creating urls like this:
 * http://[servername]/[appname
 * ]/resources/org.apache.wicket.Application//pictureResource?id=[digest]
 * http://[servername]/[appname]/resources/org.apache.wicket.Application//
 * pictureResource?id=[digest]&layout
 * http://[servername]/[appname]/resources/org
 * .apache.wicket.Application//pictureResource?id=[digest]&thumb
 * 
 * Diese Urls are bookmarkeable.
 * 
 * @author Ingo Renner
 * @author Henning Teek
 * 
 */
public class PictureResource extends DynamicWebResource {
    private final Logger log = LoggerFactory.getLogger(PictureResource.class);

    private static final String LAYOUT = "layout";

    private static final String THUMB = "thumb";

    private static final String ID = "id";

    @SpringBean
    private PictureModificationService pictureModificationService;

    protected static final String FORMAT = "jpg";

    public static final String PICTURE_RESOURCE = "/pictureResource";

    public PictureResource() {
        super();
        log.info("injecting 1");
        InjectorHolder.getInjector().inject(this);
    }

    public PictureResource(Locale local) {
        super(local);
        log.info("injecting 2");
        InjectorHolder.getInjector().inject(this);
    }

    public static String getUrl(String digest) {
        final ResourceReference imageResource = new ResourceReference(PICTURE_RESOURCE);
        return RequestCycle.get().urlFor(imageResource) + "?" + ID + "=" + digest;
    }

    public static String getLayoutUrl(String digest) {
        ResourceReference imageResource = new ResourceReference(PICTURE_RESOURCE);
        return RequestCycle.get().urlFor(imageResource) + "?" + ID + "=" + digest + "&" + LAYOUT;
    }

    public static String getThumbnailUrl(String digest) {
        ResourceReference imageResource = new ResourceReference(PICTURE_RESOURCE);
        return RequestCycle.get().urlFor(imageResource) + "?" + ID + "=" + digest + "&" + THUMB;
    }

    private File getImageFile(ValueMap params) {
        log.info("injecting getImageFile");
        InjectorHolder.getInjector().inject(this);
        if (params.containsKey(ID)) {
            final String digest = params.getString(ID);
            log.info("digest=" + digest);
            log.info("pictureModificationService=" + pictureModificationService);
            if (isThumbnail(params)) {
                return pictureModificationService.getThumbnailImage(digest);
            } else {
                if (isLayout(params)) {
                    return pictureModificationService.getLayoutImage(digest);
                } else {
                    return pictureModificationService.getImage(digest);
                }
            }
        }
        return null;
    }

    private boolean isThumbnail(ValueMap params) {
        return params.containsKey(THUMB);
    }

    private boolean isLayout(ValueMap params) {
        return params.containsKey(LAYOUT);
    }

    protected byte[] getImageData() {
        ValueMap params = getParameters();
        File file = getImageFile(params);
        if (file != null) {
            try {
                return IOUtils.toByteArray(new FileInputStream(file));
            } catch (FileNotFoundException e) {
                log.error("file not found", e);
            } catch (IOException e) {
                log.error("io error", e);
            }
        }
        log.error("No image data available.");
        return new byte[0];
    }

    protected Time getImageLastModified() {
        ValueMap params = getParameters();
        File file = getImageFile(params);
        if (file != null) {
            return Time.valueOf(file.lastModified());
        }
        return null;
    }

    @Override
    protected synchronized ResourceState getResourceState() {
        return new ResourceState() {
            private byte[] imageData;

            @Override
            public Time lastModifiedTime() {
                if (lastModifiedTime == null) {
                    lastModifiedTime = getImageLastModified();
                    if (lastModifiedTime == null) {
                        lastModifiedTime = Time.now();
                    }
                }
                return lastModifiedTime;
            }

            @Override
            public byte[] getData() {
                if (imageData == null) {
                    imageData = getImageData();
                }
                return imageData;
            }

            @Override
            public String getContentType() {
                return "image/" + FORMAT;
            }
        };
    }
}