at.ait.dme.yuma.suite.apps.map.server.tileset.TilesetGenerator.java Source code

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Here is the source code for at.ait.dme.yuma.suite.apps.map.server.tileset.TilesetGenerator.java

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/*
 * Copyright 2008-2010 Austrian Institute of Technology
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they
 * will be approved by the European Commission - subsequent
 * versions of the EUPL (the "Licence");
 * you may not use this work except in compliance with the
 * Licence.
 * You may obtain a copy of the Licence at:
 *
 * http://ec.europa.eu/idabc/eupl
 *
 * Unless required by applicable law or agreed to in
 * writing, software distributed under the Licence is
 * distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied.
 * See the Licence for the specific language governing
 * permissions and limitations under the Licence.
 */

package at.ait.dme.yuma.suite.apps.map.server.tileset;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.log4j.Logger;

import at.ait.dme.magicktiler.MagickTiler;
import at.ait.dme.magicktiler.tms.TMSTiler;
import at.ait.dme.yuma.suite.apps.map.shared.Tileset;
import at.ait.dme.yuma.suite.apps.map.shared.server.exception.TilingException;

/**
 * This class uses MagickTiler to generate TMS tiles for
 * images on the fly.
 * 
 * @author Christian Sadilek
 */
public class TilesetGenerator {

    private static Logger logger = Logger.getLogger(TilesetGenerator.class);

    private static String rootPath = null;

    public static void init(String tilesRootPath) {
        rootPath = tilesRootPath;
    }

    /**
     * Generates TMS tiles for the image with the given URL using
     * MagickTiler (http://code.google.com/p/magicktiler).
     * 
     * @param url the image URL
     * @return tileset the tileset
     * @throws TilingException if anything goes wrong
     */
    public Tileset renderTiles(String url) throws TilingException {
        try {
            String tilesDir = rootPath + "/" + createTilesetPath(url);

            if (new File(tilesDir).mkdir()) {
                String imageFile = downloadImage(tilesDir, url);
                MagickTiler tiler = new TMSTiler();
                tiler.convert(new File(imageFile), new File(tilesDir));
            }

            FileReader reader = new FileReader(new File(tilesDir + "/tilemapresource.xml"));
            return new TileschemeParser().parseTMSDescriptor("tilesets/" + createTilesetPath(url) + "/", reader);
        } catch (Throwable t) {
            logger.fatal(t.getMessage(), t);
            throw new TilingException(t);
        }
    }

    private String downloadImage(String dir, String url) throws TilingException {
        InputStream is = null;
        OutputStream os = null;

        try {
            GetMethod getImageMethod = new GetMethod(url);
            int statusCode = new HttpClient().executeMethod(getImageMethod);
            if (statusCode != HttpStatus.SC_OK)
                throw new TilingException("GET " + url + " returned status code:" + statusCode);

            is = getImageMethod.getResponseBodyAsStream();
            File imageFile = new File(dir + "/" + url.substring(url.lastIndexOf("/")).replace("%", "-"));
            os = new FileOutputStream(imageFile);

            byte buf[] = new byte[1024];
            int len;
            while ((len = is.read(buf)) > 0)
                os.write(buf, 0, len);

            return imageFile.getAbsolutePath();
        } catch (Throwable t) {
            logger.error("failed to store image from url:" + url, t);
            throw new TilingException(t);
        } finally {
            try {
                if (os != null)
                    os.close();
                if (is != null)
                    is.close();
            } catch (IOException e) {
                logger.error("failed to close streams");
            }

        }
    }

    public static boolean tilesetExists(String imageUrl) {
        return new File(rootPath + "/" + TilesetGenerator.createTilesetPath(imageUrl)).exists();
    }

    public static String createTilesetPath(String imageUrl) {
        String path = imageUrl.replaceAll("[^(A-Za-z0-9)]+", "-");
        if (path.length() > 255)
            path = path.substring(path.length() - 255);
        return path;
    }

    public static String getRootPath() {
        return rootPath;
    }

}