org.aspectj/bcel-builder/src/main/java/org/aspectj/apache/bcel/generic/ObjectType.java

package org.aspectj.apache.bcel.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * 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
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * 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 org.aspectj.apache.bcel.Constants;
import org.aspectj.apache.bcel.Repository;
import org.aspectj.apache.bcel.classfile.JavaClass;

/**
 * Denotes reference such as java.lang.String.
 *
 * @version $Id: ObjectType.java,v 1.7 2009/09/28 16:39:46 aclement Exp $
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public class ObjectType extends ReferenceType {
	private String classname;

	/**
	 * @param class_name fully qualified class name, e.g. java.lang.String
	 */
	public ObjectType(String class_name) {
		super(Constants.T_REFERENCE, toSignature(class_name));// "L" + class_name.replace('.', '/') + ";");
		this.classname = class_name;// .replace('/', '.');
	}

	/**
	 * @param classname eg. java.lang.String
	 * @param signature eg. Ljava/lang/String;
	 */
	public ObjectType(String classname, String signature) {
		super(Constants.T_REFERENCE, signature);
		this.classname = classname;
	}

	private static String toSignature(String classname) {
		StringBuilder sig = new StringBuilder();
		sig.append("L").append(classname.replace('.', '/'));
		sig.append(";");
		return sig.toString();
	}

	/**
	 * @return name of referenced class
	 */
	public String getClassName() {
		return classname;
	}

	/**
	 * @return a hash code value for the object.
	 */
	@Override
	public int hashCode() {
		return classname.hashCode();
	}

	/**
	 * @return true if both type objects refer to the same class.
	 */
	@Override
	public boolean equals(Object type) {
		return (type instanceof ObjectType) ? ((ObjectType) type).classname.equals(classname) : false;
	}

	/**
	 * If "this" doesn't reference a class, it references an interface or a non-existant entity.
	 */
	public boolean referencesClass() {
		JavaClass jc = Repository.lookupClass(classname);
		if (jc == null) {
			return false;
		} else {
			return jc.isClass();
		}
	}

	/**
	 * If "this" doesn't reference an interface, it references a class or a non-existant entity.
	 */
	public boolean referencesInterface() {
		JavaClass jc = Repository.lookupClass(classname);
		if (jc == null) {
			return false;
		} else {
			return !jc.isClass();
		}
	}

	public boolean subclassOf(ObjectType superclass) {
		if (this.referencesInterface() || superclass.referencesInterface()) {
			return false;
		}

		return Repository.instanceOf(this.classname, superclass.classname);
	}

	/**
	 * Java Virtual Machine Specification edition 2, 5.4.4 Access Control
	 */
	public boolean accessibleTo(ObjectType accessor) {
		JavaClass jc = Repository.lookupClass(classname);

		if (jc.isPublic()) {
			return true;
		} else {
			JavaClass acc = Repository.lookupClass(accessor.classname);
			return acc.getPackageName().equals(jc.getPackageName());
		}
	}
}