imgcoverageresponsedelegate.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.gce.image.WorldImageWriter;
import org.geotools.image.ImageWorker;
import org.opengis.coverage.grid.Format;
import org.opengis.coverage.grid.GridCoverageWriter;
import org.opengis.parameter.GeneralParameterValue;
import org.vfny.geoserver.ServiceException;
import org.vfny.geoserver.global.GeoServer;
import org.vfny.geoserver.wcs.responses.CoverageResponseDelegate;
import java.awt.image.ComponentColorModel;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.MemoryCacheImageOutputStream;
import javax.media.jai.PlanarImage;


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

    public IMGCoverageResponseDelegate() {
    }

    public boolean canProduce(String outputFormat) {
        if (outputFormat.equalsIgnoreCase("bmp") || outputFormat.equalsIgnoreCase("gif")
                || outputFormat.equalsIgnoreCase("tiff") || outputFormat.equalsIgnoreCase("png")
                || outputFormat.equalsIgnoreCase("jpeg") || outputFormat.equalsIgnoreCase("tif")) {
            return true;
        }

        return false;
    }

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

    public String getContentType(GeoServer gs) {
        return new StringBuffer("image/").append(outputFormat.toLowerCase()).toString();
    }

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

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getContentDisposition() {
        return (outputFormat.equalsIgnoreCase("tiff") || outputFormat.equalsIgnoreCase("tif"))
        ? new StringBuffer("attachment;filename=").append(this.sourceCoverage.getName()).append(".")
                                                  .append(outputFormat).toString() : null;
    }

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

        final GridCoverageWriter writer = new WorldImageWriter(output);

        // writing parameters for Image
        final Format writerParams = writer.getFormat();
        writerParams.getWriteParameters().parameter("Format")
                    .setValue(this.outputFormat.toLowerCase());

        // writing
        writer.write(sourceCoverage,
            (GeneralParameterValue[]) writerParams.getWriteParameters().values()
                                                  .toArray(new GeneralParameterValue[1]));

        // freeing everything
        writer.dispose();
        this.sourceCoverage.dispose();
        this.sourceCoverage = null;
    }
}