geotiffcoverageresponsedelegate.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org.  All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.vfny.geoserver.wcs.responses.coverage;

import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.grid.io.AbstractGridFormat;
import org.geotools.coverage.grid.io.imageio.GeoToolsWriteParams;
import org.geotools.gce.geotiff.GeoTiffFormat;
import org.geotools.gce.geotiff.GeoTiffWriteParams;
import org.opengis.coverage.grid.GridCoverageWriter;
import org.opengis.parameter.GeneralParameterValue;
import org.opengis.parameter.ParameterValueGroup;
import org.vfny.geoserver.ServiceException;
import org.vfny.geoserver.global.GeoServer;
import org.vfny.geoserver.wcs.responses.CoverageResponseDelegate;
import java.io.IOException;
import java.io.OutputStream;


/**
 * DOCUMENT ME!
 *
 * @author $Author: Alessio Fabiani ([e-mail]) $ (last
 *         modification)
 * @author $Author: Simone Giannecchini ([e-mail]) $ (last
 *         modification)
 */
public class GeoTIFFCoverageResponseDelegate implements CoverageResponseDelegate {
    /**
     *
     * @uml.property name="sourceCoverage"
     * @uml.associationEnd multiplicity="(0 1)"
     */
    private GridCoverage2D sourceCoverage;

    public GeoTIFFCoverageResponseDelegate() {
    }

    public boolean canProduce(String outputFormat) {
        if (outputFormat.equalsIgnoreCase("geotiff")) {
            return true;
        }

        return false;
    }

    public void prepare(String outputFormat, GridCoverage2D coverage)
        throws IOException {
        this.sourceCoverage = coverage;
    }

    public String getContentType(GeoServer gs) {
        return "image/tiff";
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getContentEncoding() {
        return null;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getContentDisposition() {
        return "attachment;filename=" + this.sourceCoverage.getName() + ".tiff";
    }

    public void encode(OutputStream output) throws ServiceException, IOException {
        if (sourceCoverage == null) {
            throw new IllegalStateException("It seems prepare() has not been called"
                + " or has not succeed");
        }

        final GeoTiffFormat format = new GeoTiffFormat();
        final GeoTiffWriteParams wp = new GeoTiffWriteParams();
        wp.setCompressionMode(GeoTiffWriteParams.MODE_EXPLICIT);
        wp.setCompressionType("LZW");
        wp.setCompressionQuality(0.75F);
        wp.setTilingMode(GeoToolsWriteParams.MODE_EXPLICIT);
        wp.setTiling(256, 256);

        final ParameterValueGroup writerParams = format.getWriteParameters();
        writerParams.parameter(AbstractGridFormat.GEOTOOLS_WRITE_PARAMS.getName().toString())
                    .setValue(wp);

        GridCoverageWriter writer = format.getWriter(output);
        writer.write(sourceCoverage,
            (GeneralParameterValue[]) writerParams.values().toArray(new GeneralParameterValue[1]));

        writer.dispose();

        this.sourceCoverage.dispose();
        this.sourceCoverage = null;
    }
}