    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}