MBTilesFormat.java

package org.geotools.mbtiles.mosaic;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.geotools.coverage.grid.io.AbstractGridCoverage2DReader;
import org.geotools.coverage.grid.io.AbstractGridFormat;
import org.geotools.coverage.grid.io.imageio.GeoToolsWriteParams;
import org.geotools.data.DataUtilities;
import org.geotools.factory.Hints;
import org.geotools.parameter.DefaultParameterDescriptorGroup;
import org.geotools.parameter.ParameterGroup;
import org.geotools.util.logging.Logging;
import org.opengis.coverage.grid.GridCoverageWriter;
import org.opengis.parameter.GeneralParameterDescriptor;

public class MBTilesFormat extends AbstractGridFormat {
       
    private final static Logger LOGGER = Logging.getLogger(MBTilesFormat.class.getPackage().getName());

    public static File getFileFromSource(Object source) {
        if (source == null) {
            return null;
        }

        File sourceFile = null;

        try {
            if (source instanceof File) {
                sourceFile = (File) source;
            } else if (source instanceof URL) {
                if (((URL) source).getProtocol().equals("file")){
                    sourceFile = DataUtilities.urlToFile((URL) source);
                }
            } else if (source instanceof String) {
                sourceFile = new File((String) source);
            }
        } catch (Exception e) {
            if (LOGGER.isLoggable(Level.FINE)) {
                LOGGER.log(Level.FINE, e.getLocalizedMessage(), e);
            }

            return null;
        }

        return sourceFile;
    }

    @Override
    public AbstractGridCoverage2DReader getReader(Object source) {
        return getReader(source, null);
    }

    @Override
    public AbstractGridCoverage2DReader getReader(Object source, Hints hints) {
        try {
            return new MBTilesReader(source, hints);
        } catch (IOException e) {
            LOGGER.log(Level.WARNING, e.getLocalizedMessage(), e);
            return null;
        }
    }

    @Override
    public GridCoverageWriter getWriter(Object destination) {
        return getWriter(destination, null);
    }
    
    @Override
    public GridCoverageWriter getWriter(Object destination, Hints hints) {
        throw new UnsupportedOperationException("Unsupported method: MBTiles format is read-only.");
    }

    @Override
    public boolean accepts(Object source, Hints hints) {
        if (source == null) {
            return false;
        }

       File sourceFile = getFileFromSource(source);

        if (sourceFile == null) {
            return false;
        }
        
        //TODO: check if it is proper sqlite and mbtiles file
        return sourceFile.getName().endsWith(".mbtiles");
    }

    @Override
    public GeoToolsWriteParams getDefaultImageIOWriteParameters() {
        throw new UnsupportedOperationException("Unsupported method.");
    }
    
    /**
     * Creates an instance and sets the metadata.
     */
    public MBTilesFormat() {
        setInfo();
    }

    /**
     * Sets the metadata information.
     */
    private void setInfo() {
        final HashMap<String,String> info = new HashMap<String,String> ();
        info.put("name", "MBTiles");
        info.put("description", "MBTiles plugin");
        info.put("vendor", "Geotools");
        info.put("docURL", "");
        info.put("version", "1.0");
        mInfo = info;

        // reading parameters
        readParameters = new ParameterGroup(new DefaultParameterDescriptorGroup(mInfo,
                new GeneralParameterDescriptor[]{
                        READ_GRIDGEOMETRY2D /*,
                       INPUT_TRANSPARENT_COLOR,
                OUTPUT_TRANSPARENT_COLOR,
                USE_JAI_IMAGEREAD,
                BACKGROUND_VALUES,
                SUGGESTED_TILE_SIZE,
                ALLOW_MULTITHREADING,
                MAX_ALLOWED_TILES,
                TIME,
                ELEVATION,
                FILTER,
                ACCURATE_RESOLUTION,
                SORT_BY,
                MERGE_BEHAVIOR,
                FOOTPRINT_BEHAVIOR*/
        }));

        // reading parameters
        writeParameters = null;
    }

}