001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.generic;
020
021import org.apache.bcel.Const;
022import org.apache.bcel.Repository;
023import org.apache.bcel.classfile.JavaClass;
024import org.apache.bcel.classfile.Utility;
025
026/**
027 * Denotes reference such as {@link String}.
028 */
029public class ObjectType extends ReferenceType {
030
031    /**
032     * Constructs a new instance.
033     *
034     * @param className fully qualified class name, for example {@link String}.
035     * @return a new instance.
036     * @since 6.0
037     */
038    public static ObjectType getInstance(final String className) {
039        return new ObjectType(className);
040    }
041
042    private final String className; // Class name of type
043
044    /**
045     * Constructs a new instance.
046     *
047     * @param className fully qualified class name, for example {@link String}.
048     */
049    public ObjectType(final String className) {
050        super(Const.T_REFERENCE, "L" + Utility.packageToPath(className) + ";");
051        this.className = Utility.pathToPackage(className);
052    }
053
054    /**
055     * Java Virtual Machine Specification edition 2, � 5.4.4 Access Control
056     *
057     * @throws ClassNotFoundException if the class referenced by this type can't be found
058     */
059    public boolean accessibleTo(final ObjectType accessor) throws ClassNotFoundException {
060        final JavaClass jc = Repository.lookupClass(className);
061        if (jc.isPublic()) {
062            return true;
063        }
064        final JavaClass acc = Repository.lookupClass(accessor.className);
065        return acc.getPackageName().equals(jc.getPackageName());
066    }
067
068    /**
069     * @return true if both type objects refer to the same class.
070     */
071    @Override
072    public boolean equals(final Object type) {
073        return type instanceof ObjectType && ((ObjectType) type).className.equals(className);
074    }
075
076    /**
077     * @return name of referenced class.
078     */
079    @Override
080    public String getClassName() {
081        return className;
082    }
083
084    /**
085     * @return a hash code value for the object.
086     */
087    @Override
088    public int hashCode() {
089        return className.hashCode();
090    }
091
092    /**
093     * If "this" doesn't reference a class, it references an interface or a non-existant entity.
094     *
095     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
096     *             found: use referencesClassExact() instead
097     */
098    @Deprecated
099    public boolean referencesClass() {
100        try {
101            final JavaClass jc = Repository.lookupClass(className);
102            return jc.isClass();
103        } catch (final ClassNotFoundException e) {
104            return false;
105        }
106    }
107
108    /**
109     * Return true if this type references a class, false if it references an interface.
110     *
111     * @return true if the type references a class, false if it references an interface.
112     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
113     */
114    public boolean referencesClassExact() throws ClassNotFoundException {
115        final JavaClass jc = Repository.lookupClass(className);
116        return jc.isClass();
117    }
118
119    /**
120     * If "this" doesn't reference an interface, it references a class or a non-existant entity.
121     *
122     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
123     *             found: use referencesInterfaceExact() instead
124     */
125    @Deprecated
126    public boolean referencesInterface() {
127        try {
128            final JavaClass jc = Repository.lookupClass(className);
129            return !jc.isClass();
130        } catch (final ClassNotFoundException e) {
131            return false;
132        }
133    }
134
135    /**
136     * Return true if this type references an interface, false if it references a class.
137     *
138     * @return true if the type references an interface, false if it references a class.
139     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
140     */
141    public boolean referencesInterfaceExact() throws ClassNotFoundException {
142        final JavaClass jc = Repository.lookupClass(className);
143        return !jc.isClass();
144    }
145
146    /**
147     * Return true if this type is a subclass of given ObjectType.
148     *
149     * @throws ClassNotFoundException if any of this class's superclasses can't be found
150     */
151    public boolean subclassOf(final ObjectType superclass) throws ClassNotFoundException {
152        if (referencesInterfaceExact() || superclass.referencesInterfaceExact()) {
153            return false;
154        }
155        return Repository.instanceOf(this.className, superclass.className);
156    }
157}