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 */
017package org.apache.bcel.generic;
018
019import org.apache.bcel.Const;
020import org.apache.bcel.Repository;
021import org.apache.bcel.classfile.JavaClass;
022import org.apache.bcel.classfile.Utility;
023
024/**
025 * Denotes reference such as java.lang.String.
026 */
027public class ObjectType extends ReferenceType {
028
029    /**
030     * @since 6.0
031     */
032    public static ObjectType getInstance(final String className) {
033        return new ObjectType(className);
034    }
035
036    private final String className; // Class name of type
037
038    /**
039     * @param className fully qualified class name, e.g. java.lang.String
040     */
041    public ObjectType(final String className) {
042        super(Const.T_REFERENCE, "L" + className.replace('.', '/') + ";");
043        this.className = Utility.pathToPackage(className);
044    }
045
046    /**
047     * Java Virtual Machine Specification edition 2, � 5.4.4 Access Control
048     *
049     * @throws ClassNotFoundException if the class referenced by this type can't be found
050     */
051    public boolean accessibleTo(final ObjectType accessor) throws ClassNotFoundException {
052        final JavaClass jc = Repository.lookupClass(className);
053        if (jc.isPublic()) {
054            return true;
055        }
056        final JavaClass acc = Repository.lookupClass(accessor.className);
057        return acc.getPackageName().equals(jc.getPackageName());
058    }
059
060    /**
061     * @return true if both type objects refer to the same class.
062     */
063    @Override
064    public boolean equals(final Object type) {
065        return type instanceof ObjectType && ((ObjectType) type).className.equals(className);
066    }
067
068    /**
069     * @return name of referenced class
070     */
071    public String getClassName() {
072        return className;
073    }
074
075    /**
076     * @return a hash code value for the object.
077     */
078    @Override
079    public int hashCode() {
080        return className.hashCode();
081    }
082
083    /**
084     * If "this" doesn't reference a class, it references an interface or a non-existant entity.
085     *
086     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
087     *             found: use referencesClassExact() instead
088     */
089    @Deprecated
090    public boolean referencesClass() {
091        try {
092            final JavaClass jc = Repository.lookupClass(className);
093            return jc.isClass();
094        } catch (final ClassNotFoundException e) {
095            return false;
096        }
097    }
098
099    /**
100     * Return true if this type references a class, false if it references an interface.
101     *
102     * @return true if the type references a class, false if it references an interface
103     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
104     */
105    public boolean referencesClassExact() throws ClassNotFoundException {
106        final JavaClass jc = Repository.lookupClass(className);
107        return jc.isClass();
108    }
109
110    /**
111     * If "this" doesn't reference an interface, it references a class or a non-existant entity.
112     *
113     * @deprecated (since 6.0) this method returns an inaccurate result if the class or interface referenced cannot be
114     *             found: use referencesInterfaceExact() instead
115     */
116    @Deprecated
117    public boolean referencesInterface() {
118        try {
119            final JavaClass jc = Repository.lookupClass(className);
120            return !jc.isClass();
121        } catch (final ClassNotFoundException e) {
122            return false;
123        }
124    }
125
126    /**
127     * Return true if this type references an interface, false if it references a class.
128     *
129     * @return true if the type references an interface, false if it references a class
130     * @throws ClassNotFoundException if the class or interface referenced by this type can't be found
131     */
132    public boolean referencesInterfaceExact() throws ClassNotFoundException {
133        final JavaClass jc = Repository.lookupClass(className);
134        return !jc.isClass();
135    }
136
137    /**
138     * Return true if this type is a subclass of given ObjectType.
139     *
140     * @throws ClassNotFoundException if any of this class's superclasses can't be found
141     */
142    public boolean subclassOf(final ObjectType superclass) throws ClassNotFoundException {
143        if (this.referencesInterfaceExact() || superclass.referencesInterfaceExact()) {
144            return false;
145        }
146        return Repository.instanceOf(this.className, superclass.className);
147    }
148}