    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}