FileRasterFilter.java

/**
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * @author Arne Kepp, OpenGeo, Copyright 2009
 */
package org.geowebcache.filter.request;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.imageio.ImageIO;

import org.geowebcache.GeoWebCacheException;
import org.geowebcache.layer.TileLayer;

public class FileRasterFilter extends RasterFilter {

    private static final long serialVersionUID = -6950985531575208956L;

    private String storagePath;
    
    private String fileExtension;

    /**
     * @return the storagePath
     */
    String getStoragePath() {
        return storagePath;
    }

    /**
     * @param storagePath the storagePath to set
     */
    void setStoragePath(String storagePath) {
        this.storagePath = storagePath;
    }

    /**
     * @return the fileExtension
     */
    String getFileExtension() {
        return fileExtension;
    }

    /**
     * @param fileExtension the fileExtension to set
     */
    void setFileExtension(String fileExtension) {
        this.fileExtension = fileExtension;
    }

    protected BufferedImage loadMatrix(TileLayer layer, String gridSetId, int zoomLevel)
    throws IOException, GeoWebCacheException {
        File fh = new File( createFilePath(gridSetId, zoomLevel) );
        
        if(! fh.exists() || ! fh.canRead()) {
            throw new GeoWebCacheException(fh.getAbsolutePath() + " does not exist or is not readable");
        }
        
        BufferedImage img = ImageIO.read(fh);
        
        int[] widthHeight = calculateWidthHeight(layer.getGridSubset(gridSetId), zoomLevel);
        
        if(img.getWidth() != widthHeight[0] || img.getHeight() != widthHeight[1]) {
            String msg = fh.getAbsolutePath() + " has dimensions " + img.getWidth() + "," + img.getHeight()
            + ", expected " + widthHeight[0] + "," + widthHeight[1];
            throw new GeoWebCacheException(msg);
        }
        
        return img;
    }
    
    private String createFilePath(String gridSetId, int zoomLevel) {
        String path =  
            storagePath + File.separator 
            + this.getName() + "_" + gridSetId 
            + "_" + zoomLevel + "." + fileExtension;
        
        return path;
    }
    
    public void saveMatrix(byte[] data, TileLayer layer, String gridSetId, int zoomLevel) throws IOException {
        // Persist
        File fh = new File(createFilePath(gridSetId, zoomLevel) );
        FileOutputStream fos = new FileOutputStream(fh);
        fos.write(data);
        fos.close();
    }

    public void update(byte[] filterData, TileLayer layer, String gridSetId, int z)
            throws GeoWebCacheException {
        try {
            saveMatrix(filterData, layer, gridSetId, z);
            
        } catch (IOException e) {
            throw new GeoWebCacheException(this.getName() 
                    + " encountered an error while persisting matrix, " + e.getMessage());
        }
        
        try {
            super.setMatrix(layer, gridSetId, z, true);
        } catch (IOException e) {
            throw new GeoWebCacheException(this.getName() 
                    + " encountered an error while loading matrix, " + e.getMessage());
        }
    }

    
    public void update(TileLayer layer, String gridSetId, int zoomStart, int zoomStop)
            throws GeoWebCacheException {
        throw new GeoWebCacheException("TileLayer layer, String gridSetId, int z) is not appropriate for FileRasterFilters");
    }
    
    public boolean update(TileLayer layer, String gridSetId ) {
        return false;
    }
}