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;
023
024/**
025 * Denotes reference such as java.lang.String.
026 *
027 * @version $Id: ObjectType.java 1806200 2017-08-25 16:33:06Z ggregory $
028 */
029public class ObjectType extends ReferenceType {
030
031    private final String class_name; // Class name of type
032
033    /**
034     * @since 6.0
035     */
036    public static ObjectType getInstance(final String class_name) {
037        return new ObjectType(class_name);
038    }
039
040    /**
041     * @param class_name fully qualified class name, e.g. java.lang.String
042     */
043    public ObjectType(final String class_name) {
044        super(Const.T_REFERENCE, "L" + class_name.replace('.', '/') + ";");
045        this.class_name = class_name.replace('/', '.');
046    }
047
048
049    /** @return name of referenced class
050     */
051    public String getClassName() {
052        return class_name;
053    }
054
055
056    /** @return a hash code value for the object.
057     */
058    @Override
059    public int hashCode() {
060        return class_name.hashCode();
061    }
062
063
064    /** @return true if both type objects refer to the same class.
065     */
066    @Override
067    public boolean equals( final Object type ) {
068        return (type instanceof ObjectType)
069                ? ((ObjectType) type).class_name.equals(class_name)
070                : false;
071    }
072
073
074    /**
075     * If "this" doesn't reference a class, it references an interface
076     * or a non-existant entity.
077     * @deprecated (since 6.0) this method returns an inaccurate result
078     *   if the class or interface referenced cannot
079     *   be found: use referencesClassExact() instead
080     */
081    @Deprecated
082    public boolean referencesClass() {
083        try {
084            final JavaClass jc = Repository.lookupClass(class_name);
085            return jc.isClass();
086        } catch (final ClassNotFoundException e) {
087            return false;
088        }
089    }
090
091
092    /**
093     * If "this" doesn't reference an interface, it references a class
094     * or a non-existant entity.
095     * @deprecated (since 6.0) this method returns an inaccurate result
096     *   if the class or interface referenced cannot
097     *   be found: use referencesInterfaceExact() instead
098     */
099    @Deprecated
100    public boolean referencesInterface() {
101        try {
102            final JavaClass jc = Repository.lookupClass(class_name);
103            return !jc.isClass();
104        } catch (final ClassNotFoundException e) {
105            return false;
106        }
107    }
108
109
110    /**
111     * Return true if this type references a class,
112     * false if it references an interface.
113     * @return true if the type references a class, false if
114     *   it references an interface
115     * @throws ClassNotFoundException if the class or interface
116     *   referenced by this type can't be found
117     */
118    public boolean referencesClassExact() throws ClassNotFoundException {
119        final JavaClass jc = Repository.lookupClass(class_name);
120        return jc.isClass();
121    }
122
123
124    /**
125     * Return true if this type references an interface,
126     * false if it references a class.
127     * @return true if the type references an interface, false if
128     *   it references a class
129     * @throws ClassNotFoundException if the class or interface
130     *   referenced by this type can't be found
131     */
132    public boolean referencesInterfaceExact() throws ClassNotFoundException {
133        final JavaClass jc = Repository.lookupClass(class_name);
134        return !jc.isClass();
135    }
136
137
138    /**
139     * Return true if this type is a subclass of given ObjectType.
140     * @throws ClassNotFoundException if any of this class's superclasses
141     *  can't be found
142     */
143    public boolean subclassOf( final ObjectType superclass ) throws ClassNotFoundException {
144        if (this.referencesInterfaceExact() || superclass.referencesInterfaceExact()) {
145            return false;
146        }
147        return Repository.instanceOf(this.class_name, superclass.class_name);
148    }
149
150
151    /**
152     * Java Virtual Machine Specification edition 2, � 5.4.4 Access Control
153     * @throws ClassNotFoundException if the class referenced by this type
154     *   can't be found
155     */
156    public boolean accessibleTo( final ObjectType accessor ) throws ClassNotFoundException {
157        final JavaClass jc = Repository.lookupClass(class_name);
158        if (jc.isPublic()) {
159            return true;
160        }
161        final JavaClass acc = Repository.lookupClass(accessor.class_name);
162        return acc.getPackageName().equals(jc.getPackageName());
163    }
164}