environment.java

Java Communicating Agents是一个用于开发网络反应式信息agent的框架

/*
 * $Source: /home/data/cvsroot/src/jacomma/util/Environment.java,v $
 * $Revision: 1.11 $
 * $Date: 2000/10/28 20:09:08 $
 *
 * This file is part of the jacomma framework
 * Copyright (c) 2000 	Dimitrios Vyzovitis
 *			mailto:[e-mail]
 *			
 *
 *			
 *			
 *			
 *
 *	This library is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU Library General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	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 Library General Public License for more details.
 *
 *	You should have received a copy of the GNU Library General Public License
 *	along with this library; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, 
 *	Boston, MA  02111-1307  USA
 */

package jacomma.util;

import java.net.URL;

/**
 * TBA
 **/
public final class Environment {

	public static final boolean DEBUG;
	
	static final Cache lpcache_;
	static final java.util.Hashtable prop_;

	static {
		DEBUG = true;
		lpcache_ = new Cache();
		prop_ = loadProperties( Environment.class );
	}

	public static Object setProperty( String key, Object val ) {
		return prop_.put( key, val );
	}
	
	public static Object getProperty( String key ) {
		return prop_.get( key );
	}

	public synchronized static final void outp( Object obj ) {
		if ( DEBUG ) {
			System.out.println( new java.util.Date() + ":" + Thread.currentThread() 
								+ ":" + obj );
			System.out.flush();
		}
	}
	
	public static void assert( boolean b, String msg ) {
		if ( DEBUG && !b ) {
			outp( msg + ": Assertion failed!" );
			throw new RuntimeException( "Assertion failed!" );
		}
	}
	
	public static final Object newInstance( String c ) {
		try {
			return Class.forName( c ).newInstance();
		} catch ( ClassNotFoundException exc ) {
			throw new CheckedException( exc );
		} catch ( InstantiationException exc ) {
			throw new CheckedException( exc );
		} catch ( IllegalAccessException exc ) {
			throw new CheckedException( exc );
		}
	}

	public static final Object newInstance( Class c ) {
		try {
			return c.newInstance();
		} catch ( InstantiationException exc ) {
			throw new CheckedException( exc );
		} catch ( IllegalAccessException exc ) {
			throw new CheckedException( exc );
		}
	}
	
	public static final Object newRegistry( Class c ) {
		try {
			java.util.Properties p = loadProperties( c );
			Object r = Class.forName( p.getProperty( "registry" ) ).newInstance();
			r.getClass().getMethod( "load", new Class[]{java.util.Properties.class} ).invoke( r, new Object[]{p} );
			
			return r;
		} catch ( RuntimeException exc ) {
			throw exc;
		} catch ( Exception exc ) {
			throw new CheckedException( exc );
		}
	}

	public static final Object newSingleton( Class c ) {
		try {
			java.util.Properties p = loadProperties( c );
			Object r = Class.forName( p.getProperty( "instance" ) ).newInstance();
			r.getClass().getMethod( "load", new Class[]{java.util.Properties.class} ).invoke( r, new Object[]{p} );
			
			return r;
		} catch ( RuntimeException exc ) {
			throw exc;
		} catch ( Exception exc ) {
			throw new CheckedException( exc );
		}
	}

	public static java.util.Properties loadProperties( Class c ) {
		try {
			java.util.Properties p = (java.util.Properties)lpcache_.get( c );

			if ( p == null ) {
				p = new java.util.Properties();
				String f = "/resources/" 
					+ c.getName().replace( '.', '/' ) 
					+ ".properties";
				
				java.io.InputStream sin = c.getResourceAsStream( f );
								
				p.load( sin );
				sin.close();
				lpcache_.put( c, p );
			}

			return p;

		} catch ( java.io.IOException exc ) {
			exc.printStackTrace();
			throw new CheckedException( "Unable to load properties for "
										+ c.getName()
										+ " [" + exc.getMessage() + "]",
										exc );
		}
	}

	public static java.util.Properties reloadProperties( Class c ) {
		try {
			java.util.Properties p = new java.util.Properties();
			String f = "/resources/" 
				+ c.getName().replace( '.', '/' ) 
				+ ".properties";
			
			java.io.InputStream sin = c.getResourceAsStream( f );
			
			p.load( sin );
			sin.close();
			lpcache_.put( c, p );
			
			return p;

		} catch ( java.io.IOException exc ) {
			exc.printStackTrace();
			throw new CheckedException( "Unable to load properties for "
										+ c.getName()
										+ " [" + exc.getMessage() + "]",
										exc );
		}
	}
	
}