package org.aspectj.apache.bcel.util;

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 * The Apache Software License, Version 1.1
 *
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 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.WeakHashMap;

import org.aspectj.apache.bcel.classfile.ClassParser;
import org.aspectj.apache.bcel.classfile.JavaClass;

This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded from the
file systems using the paths specified in the given class path. By default, this is the value returned by
ClassPath.getClassPath(). 

It is designed to be used as a singleton, however it can also be used with custom classpaths.
/** Abstract definition of a class repository. Instances may be used to load classes from different sources and may be used in
the Repository.setRepository method.
Author:
M. Dahm, David Dixon-Peugh
See Also:
Repository
Version:
$Id: SyntheticRepository.java,v 1.8 2009/09/09 19:56:20 aclement Exp $/**
 * This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded from the
 * file systems using the paths specified in the given class path. By default, this is the value returned by
 * ClassPath.getClassPath(). <br>
 * It is designed to be used as a singleton, however it can also be used with custom classpaths.
 * 
 * /** Abstract definition of a class repository. Instances may be used to load classes from different sources and may be used in
 * the Repository.setRepository method.
 * 
 * @see org.aspectj.apache.bcel.Repository
 * 
 * @version $Id: SyntheticRepository.java,v 1.8 2009/09/09 19:56:20 aclement Exp $
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @author David Dixon-Peugh
 */
public class SyntheticRepository implements Repository {
	private static final String DEFAULT_PATH = ClassPath.getClassPath();

	private static HashMap<ClassPath, SyntheticRepository> _instances = new HashMap<ClassPath, SyntheticRepository>(); // CLASSPATH
																														// X
																														// REPOSITORY

	private ClassPath _path = null;
	private WeakHashMap<String, JavaClass> _loadedClasses = new WeakHashMap<String, JavaClass>(); // CLASSNAME X JAVACLASS

	private SyntheticRepository(ClassPath path) {
		_path = path;
	}

	public static SyntheticRepository getInstance() {
		return getInstance(ClassPath.getSystemClassPath());
	}

	public static SyntheticRepository getInstance(ClassPath classPath) {
		SyntheticRepository rep = _instances.get(classPath);

		if (rep == null) {
			rep = new SyntheticRepository(classPath);
			_instances.put(classPath, rep);
		}

		return rep;
	}

	
Store a new JavaClass instance into this Repository.
/**
	 * Store a new JavaClass instance into this Repository.
	 */
	public void storeClass(JavaClass clazz) {
		_loadedClasses.put(clazz.getClassName(), clazz);
		clazz.setRepository(this);
	}

	
Remove class from repository
/**
	 * Remove class from repository
	 */
	public void removeClass(JavaClass clazz) {
		_loadedClasses.remove(clazz.getClassName());
	}

	
Find an already defined (cached) JavaClass object by name.
/**
	 * Find an already defined (cached) JavaClass object by name.
	 */
	public JavaClass findClass(String className) {
		return _loadedClasses.get(className);
	}

	
Load a JavaClass object for the given class name using the CLASSPATH environment variable.
/**
	 * Load a JavaClass object for the given class name using the CLASSPATH environment variable.
	 */
	public JavaClass loadClass(String className) throws ClassNotFoundException {
		if (className == null || className.equals("")) {
			throw new IllegalArgumentException("Invalid class name " + className);
		}

		className = className.replace('/', '.'); // Just in case, canonical form

		try {
			return loadClass(_path.getInputStream(className), className);
		} catch (IOException e) {
			throw new ClassNotFoundException("Exception while looking for class " + className + ": " + e.toString());
		}
	}

	
Try to find class source via getResourceAsStream().
See Also:
Class
Returns:
JavaClass object for given runtime class/**
	 * Try to find class source via getResourceAsStream().
	 * 
	 * @see Class
	 * @return JavaClass object for given runtime class
	 */
	public JavaClass loadClass(Class clazz) throws ClassNotFoundException {
		String className = clazz.getName();
		String name = className;
		int i = name.lastIndexOf('.');

		if (i > 0) {
			name = name.substring(i + 1);
		}

		return loadClass(clazz.getResourceAsStream(name + ".class"), className);
	}

	private JavaClass loadClass(InputStream is, String className) throws ClassNotFoundException {
		JavaClass clazz = findClass(className);

		if (clazz != null) {
			return clazz;
		}

		try {
			if (is != null) {
				ClassParser parser = new ClassParser(is, className);
				clazz = parser.parse();

				storeClass(clazz);

				return clazz;
			}
		} catch (IOException e) {
			throw new ClassNotFoundException("Exception while looking for class " + className + ": " + e.toString());
		}

		throw new ClassNotFoundException("SyntheticRepository could not load " + className);
	}

	
Clear all entries from cache.
/**
	 * Clear all entries from cache.
	 */
	public void clear() {
		_loadedClasses.clear();
	}
}