001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.generic;
019
020import org.apache.bcel.Const;
021import org.apache.bcel.Repository;
022import org.apache.bcel.classfile.JavaClass;
023import org.apache.bcel.classfile.Utility;
024
025/**
026 * Denotes reference such as java.lang.String.
027 *
028 */
029public class ObjectType extends ReferenceType {
030
031    /**
032     * @since 6.0
033     */
034    public static ObjectType getInstance(final String className) {
035        return new ObjectType(className);
036    }
037
038    private final String className; // Class name of type
039
040    /**
041     * @param className fully qualified class name, e.g. java.lang.String
042     */
043    public ObjectType(final String className) {
044        super(Const.T_REFERENCE, "L" + className.replace('.', '/') + ";");
045        this.className = Utility.pathToPackage(className);
046    }
047
048    /**
049     * Java Virtual Machine Specification edition 2, � 5.4.4 Access Control
050     *
051     * @throws ClassNotFoundException if the class referenced by this type can't be found
052     */
053    public boolean accessibleTo(final ObjectType accessor) throws ClassNotFoundException {
054        final JavaClass jc = Repository.lookupClass(className);
055        if (jc.isPublic()) {
056            return true;
057        }
058        final JavaClass acc = Repository.lookupClass(accessor.className);
059        return acc.getPackageName().equals(jc.getPackageName());
060    }
061
062    /**
063     * @return true if both type objects refer to the same class.
064     */
065    @Override
066    public boolean equals(final Object type) {
067        return type instanceof ObjectType && ((ObjectType) type).className.equals(className);
068    }
069
070    /**
071     * @return name of referenced class
072     */
073    public String getClassName() {
074        return className;
075    }
076
077    /**
078     * @return a hash code value for the object.
079     */
080    @Override
081    public int hashCode() {
082        return className.hashCode();
083    }
084
085    /**
086     * If "this" doesn't reference a class, it references an interface or a non-existant entity.
087     *
088     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
089     *             found: use referencesClassExact() instead
090     */
091    @Deprecated
092    public boolean referencesClass() {
093        try {
094            final JavaClass jc = Repository.lookupClass(className);
095            return jc.isClass();
096        } catch (final ClassNotFoundException e) {
097            return false;
098        }
099    }
100
101    /**
102     * Return true if this type references a class, false if it references an interface.
103     *
104     * @return true if the type references a class, false if it references an interface
105     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
106     */
107    public boolean referencesClassExact() throws ClassNotFoundException {
108        final JavaClass jc = Repository.lookupClass(className);
109        return jc.isClass();
110    }
111
112    /**
113     * If "this" doesn't reference an interface, it references a class or a non-existant entity.
114     *
115     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
116     *             found: use referencesInterfaceExact() instead
117     */
118    @Deprecated
119    public boolean referencesInterface() {
120        try {
121            final JavaClass jc = Repository.lookupClass(className);
122            return !jc.isClass();
123        } catch (final ClassNotFoundException e) {
124            return false;
125        }
126    }
127
128    /**
129     * Return true if this type references an interface, false if it references a class.
130     *
131     * @return true if the type references an interface, false if it references a class
132     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
133     */
134    public boolean referencesInterfaceExact() throws ClassNotFoundException {
135        final JavaClass jc = Repository.lookupClass(className);
136        return !jc.isClass();
137    }
138
139    /**
140     * Return true if this type is a subclass of given ObjectType.
141     *
142     * @throws ClassNotFoundException if any of this class's superclasses can't be found
143     */
144    public boolean subclassOf(final ObjectType superclass) throws ClassNotFoundException {
145        if (this.referencesInterfaceExact() || superclass.referencesInterfaceExact()) {
146            return false;
147        }
148        return Repository.instanceOf(this.className, superclass.className);
149    }
150}