ScannerFactory.java

/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2015 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *   Granite Data Services 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; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   Granite Data Services 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 library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 *   USA, or see <http://www.gnu.org/licenses/>.
 */
package org.granite.scan;

import java.io.InputStream;
import java.util.Properties;

import org.granite.logging.Logger;

/**
 * @author Franck WOLFF
 */
public class ScannerFactory {
	
	private static final Logger log = Logger.getLogger(ScannerFactory.class);

	
	public static Scanner createScanner(ScannedItemHandler handler, String marker) {
        if (isVFSAvailable() && !isEmbedded() && isJBoss(5)) {
        	log.debug("Using VFS aware scanner");
        	try {
        		Class<?> vfsScannerClass = ScannerFactory.class.getClassLoader().loadClass("org.granite.scan.VFSScanner");
        		return (Scanner)vfsScannerClass.getConstructor(ScannedItemHandler.class, String.class).newInstance(handler, marker);        		
        	}
        	catch (Exception e) {
        		throw new RuntimeException("Could not create VFSScanner", e);
        	}
        }
        if (isVFS3Available()) {
        	try {
        		Class<?> vfsScannerClass = ScannerFactory.class.getClassLoader().loadClass("org.granite.scan.VFS3Scanner");
                log.debug("Using VFS3 aware scanner");
        		return (Scanner)vfsScannerClass.getConstructor(ScannedItemHandler.class, String.class).newInstance(handler, marker);
        	}
        	catch (Exception e) {
                // Not found, probably embedded
        	}
        }
        
    	log.debug("Using default scanner");
    	return new URLScanner(handler, marker);
	}
   
	private static boolean isVFSAvailable() {
		try {
			Class.forName("org.jboss.virtual.VFS");
			log.trace("VFS detected");
			return true;
		}
		catch (Throwable t) {
			return false;
		}
	}
	   
	private static boolean isVFS3Available() {
		try {
			Class.forName("org.jboss.vfs.VFS");
			log.trace("VFS3 detected");
			return true;
		}
		catch (Throwable t) {
			return false;
		}
	}
	
	private static boolean isJBoss(int version) {
		try {
			Properties props = new Properties();
			InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("/org/jboss/version.properties");
			if (is == null)
				is = Thread.currentThread().getContextClassLoader().getResourceAsStream("org/jboss/version.properties");
			if (is != null) {
				// JBoss AS 4, 5, 6
				props.load(is);
				is.close();
				int major = Integer.parseInt(props.getProperty("version.major"));
				int minor = Integer.parseInt(props.getProperty("version.minor"));
				
				boolean isJBossVersion = major >= version && minor >= 0;
				if (isJBossVersion)
					log.trace("JBoss " + major + "." + minor + " detected");
				
				return isJBossVersion;
			}
			
			// JBoss AS 7 ?
			log.trace("JBoss AS 7+ detected");
			
			return true;
		}
		catch (Throwable t) {
			return false;
		}
	}
	
	private static boolean isEmbedded() {
		try {
			ScannerFactory.class.getClassLoader().loadClass("org.jboss.embedded.Bootstrap");
			log.trace("JBoss Embedded detected");
			return true;
		}
		catch (Throwable t) {
            try {
                ScannerFactory.class.getClassLoader().loadClass("org.jboss.as.embedded.EmbeddedServerFactory");
                log.trace("JBoss AS 7+ Embedded detected");
                return true;
            }
            catch (Throwable t2) {
            }
		}
        return false;
	}
}