/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2011, Open Source Geospatial Foundation (OSGeo)
*
* This library 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;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotools.renderer.markwkt;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.Enumeration;
import java.util.Map;
import java.util.HashMap;
import java.util.Properties;
import java.io.File;
import java.io.InputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.geometry.jts.LiteShape;
import org.geotools.geometry.jts.WKTReader2;
import org.opengis.feature.Feature;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.expression.Expression;
import org.geotools.renderer.style.ExpressionExtractor;
import org.geotools.renderer.style.MarkFactory;
import org.geotools.util.SoftValueHashMap;
/**
* Factory to produce marks based on WKT representation of symbols. WKT geometries may be defined
* directly in the SLD (prefixing it with @see {@value #WKT_PREFIX}, or in a WKT library stored in a
* properties file (prefixing it with @see {@link #WKTLIB_PREFIX}).
*
* The symbols stored in properties files are cached in soft references for better
* performance. The root directory for properties files can be set using the {@link setRoot}
* method.
*
* @author Luca Morandini lmorandini@ieee.org
*
*
* @source $URL$
* @version $Id$
*
*/
public class WKTMarkFactory implements MarkFactory {
public static final String WKT_PREFIX = "wkt://";
public static final String WKTLIB_PREFIX = "wktlib://";
public static final String WKT_SEPARATOR = "#";
protected static final FilterFactory ff = CommonFactoryFinder.getFilterFactory(null);
protected static URL rootDir = null;
/** The logger for the rendering module. */
protected static final Logger LOGGER = org.geotools.util.logging.Logging
.getLogger("org.geotools.rendering");
// Cache used to store libraries of WKT geometries
protected static SoftValueHashMap<String, Map<String, String>> libraryCache;
// Initializes linrary cache
{
libraryCache = new SoftValueHashMap<String, Map<String, String>>();
}
/*
* Clears cache. While the cache uses {@link
* http://download.oracle.com/javase/1.5.0/docs/api/java/lang/ref/SoftReference.html soft
* references}, a clealring of the cache may be useful when the WKT libraries (stored in
* properties file) are updated.
*/
public void clearCache() {
libraryCache.clear();
}
/*
* Sets the root dir for WKT libraries
*
* @param root Directory from which the search for WKT libraries starts
*/
public void setRoot(URL root) {
rootDir = root;
}
/*
* Returns a WKT geometry from cache given its URL
*
* @param urlLib URL of the WKT library
*
* @param wktName name of the WKT shape
*/
protected String getFromCache(String urlLib, String wktName) {
Map<String, String> library = libraryCache.get(urlLib);
if (library != null) {
return (String) library.get(wktName);
}
return null;
}
/*
* Adds the shapes contained in a WKT library to the cache; if the url already exists in the
* cache, the shapes are not added
*
* @param urlLib URL of the WKT library as a properties file URL
*/
protected void addToCache(String urlLib) {
Map<String, String> library = libraryCache.get(urlLib);
if (library == null) {
library = new HashMap<String, String>();
Properties propLib = null;
try {
propLib = this.loadLibrary(urlLib);
} catch (IOException e1) {
LOGGER.log(Level.FINER, e1.getMessage(), e1);
}
for (Enumeration<String> e = (Enumeration<String>) propLib.propertyNames(); e
.hasMoreElements();) {
String shpName = (String) (e.nextElement());
library.put(shpName, (String) (propLib.get(shpName)));
}
libraryCache.put(urlLib, library);
}
}
/*
* Returns a WKT shaoe given that its URL specifies a WKT geometry or contains a reference to a
* WKT geometry specfied in a properties file
*
* @see org.geotools.renderer.style.MarkFactory#getShape(java.awt.Graphics2D,
* org.opengis.filter.expression.Expression, org.opengis.feature.Feature)
*/
public Shape getShape(Graphics2D graphics, Expression symbolUrl, Feature feature)
throws Exception {
// cannot handle a null url
if (symbolUrl == null) {
return null;
}
// If it does not start with either prefix, it cannot create symbols
String wellKnown = symbolUrl.evaluate(feature, String.class);
if (!wellKnown.startsWith(WKT_PREFIX) && !wellKnown.startsWith(WKTLIB_PREFIX)) {
return null;
}
// See if it is a simple WKT, so that i can extract the WKT symbols
// directly
String wkt = null;
if (wellKnown.startsWith(WKT_PREFIX)) {
wkt = wellKnown.substring(WKT_PREFIX.length());
}
// See if it is a WKT library reference
if (wellKnown.startsWith(WKTLIB_PREFIX)) {
String[] urlComponents = wellKnown.substring(WKTLIB_PREFIX.length()).split(
WKT_SEPARATOR);
wkt = this.getFromCache(urlComponents[0], urlComponents[1]);
if (wkt == null) {
this.addToCache(urlComponents[0]);
wkt = this.getFromCache(urlComponents[0], urlComponents[1]);
}
}
if (wkt == null) {
LOGGER.info("This is not recognised a WKT symbol: " + wellKnown);
}
// Creates and return the symbol
WKTReader2 reader = new WKTReader2();
LiteShape shape = new LiteShape(reader.read(wkt), null, false);
LOGGER.info("Created symbol from WKT " + wkt);
return shape;
}
/*
* Loads a WKT symbol library as a properties file
*
* @param libFilee Location of the properties file (it could be a CQL expression)
*/
protected Properties loadLibrary(String libFile) throws IOException {
final Properties properties = new Properties();
URL libUrl = null;
try {
libUrl = new URL(rootDir.toString() + "/" + libFile);
} catch (MalformedURLException e) {
LOGGER.log(Level.FINE, "Could not parse WKT library URL: " + rootDir + "/" + libFile, e);
}
InputStream in = null;
try {
in = libUrl.openStream();
properties.load(in);
} catch (FileNotFoundException e1) {
LOGGER.log(Level.FINER, e1.getMessage(), e1);
} catch (IOException e) {
LOGGER.log(Level.WARNING, e.getMessage(), e);
} finally {
in.close();
}
return properties;
}
}