CompositeMavenProjectProperties.java

/*
 * jDocBook, processing of DocBook sources as a Maven plugin
 *
 * Copyright (c) 2009, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */

package org.jboss.maven.shared.properties;

import java.util.AbstractMap;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.io.File;

import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;

/**
 * Presents an consolidated, aggregated view of project properties.
 * <p/>
 * Aggregation occurs across {@link System#getProperties()},
 * {@link org.apache.maven.project.MavenProject#getProperties()} and
 * via bean-properties-style reflection on {@link org.apache.maven.project.MavenProject}.
 *
 * @author Steve Ebersole
 */
public class CompositeMavenProjectProperties extends AbstractMap {
	private final MavenProject project;
	private final Map values;

	@SuppressWarnings("unchecked")
	public CompositeMavenProjectProperties(MavenProject project) {
		this.project = project;
		values = new HashMap( System.getProperties() );
		values.putAll( project.getProperties() );
		for ( Object o : project.getBuild().getFilters() ) {
			String filtersFile = ( String ) o;
			values.putAll( PropertiesHelper.loadPropertyFile( new File( filtersFile ) ) );
		}
	}

	public synchronized Object get(Object key) {
		// try the local value map first...
		Object value = values.get( key );

		// then try reflection on the project bean properties...
		if ( value == null ) {
			try {
				value = ReflectionValueExtractor.evaluate( String.valueOf( key ), project );
			}
			catch( Throwable ignore ) {
				// intentionally empty...
			}
		}
		return value;
	}

	public Set entrySet() {
		throw new UnsupportedOperationException( "iterating MavenProject properties is not supported" );
	}
}