pngmapproducerfactory.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.wms.responses.map.png;

import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.vfny.geoserver.global.WMS;
import org.vfny.geoserver.wms.GetMapProducer;
import org.vfny.geoserver.wms.GetMapProducerFactorySpi;

/**
 * DOCUMENT ME!
 * 
 * @author Didier Richard, IGN-F
 * @author Simone Giannecchini
 * @version $Id: PNGMapProducerFactory.java 7467 2007-08-28 22:29:03Z afabiani $
 */
public class PNGMapProducerFactory implements GetMapProducerFactorySpi {
	/** the only MIME type this map producer supports */
	static final String MIME_TYPE = "image/png";

	/**
	 * convenient singleton Set to expose the output format this producer
	 * supports
	 */
	private static final Set SUPPORTED_FORMATS;

	static {
		SUPPORTED_FORMATS = new HashSet(2);
		SUPPORTED_FORMATS.add(MIME_TYPE);
		SUPPORTED_FORMATS.add(MIME_TYPE + "8");
	}

	/**
	 * Creates a new PNGMapProducerFactory object.
	 */
	public PNGMapProducerFactory() {
		super();
	}

	/**
	 * DOCUMENT ME!
	 * 
	 * @return DOCUMENT ME!
	 */
	public String getName() {
		return "Portable Network Graphics (PNG) map producer";
	}

	/**
	 * Returns the Set of output format this producer supports
	 * 
	 * @return Set of output format this producer supports (actually
	 *         "image/png")
	 */
	public Set getSupportedFormats() {
		return SUPPORTED_FORMATS;
	}

	/**
	 * <b>FIXME</b> JAI dependency ?
	 * 
	 * @return <code>true</code>
	 */
	public boolean isAvailable() {
		return true;
	}

	/**
	 * Returns wether the map producers created by this factory can create maps
	 * in the passed output format.
	 * 
	 * @param mapFormat
	 *            a MIME type string to check if this producer is able to
	 *            handle.
	 * 
	 * @return <code>true</code> if <code>mapFormat == "image/gif"</code>,
	 *         <code>false</code> otherwise.
	 */
	public boolean canProduce(String mapFormat) {
		return SUPPORTED_FORMATS.contains(mapFormat);
	}

	/**
	 * DOCUMENT ME!
	 * 
	 * @param mapFormat
	 *            DOCUMENT ME!
	 * @param wms
	 *            DOCUMENT ME!
	 * 
	 * @return DOCUMENT ME!
	 * 
	 * @throws IllegalArgumentException
	 *             DOCUMENT ME!
	 */
	public GetMapProducer createMapProducer(String mapFormat, WMS wms)
			throws IllegalArgumentException {
		if (!canProduce(mapFormat)) {
			throw new IllegalArgumentException(new StringBuffer(mapFormat)
					.append(" not supported by this map producer").toString());
		}

		return new PNGMapProducer(mapFormat, MIME_TYPE, wms);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.geotools.factory.Factory#getImplementationHints() This just
	 *      returns java.util.Collections.EMPTY_MAP
	 */
	public Map getImplementationHints() {
		return java.util.Collections.EMPTY_MAP;
	}
}