ObjectType xref

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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.generic;
    18
    19  import org.apache.bcel.Constants;
    20  import org.apache.bcel.Repository;
    21  import org.apache.bcel.classfile.JavaClass;
    22
    23  /***
    24   * Denotes reference such as java.lang.String.
    25   *
    26   * @version $Id: ObjectType.java 386056 2006-03-15 11:31:56Z tcurdt $
    27   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    28   */
    29  public class ObjectType extends ReferenceType {
    30
    31      private String class_name; // Class name of type
    32
    33
    34      /***
    35       * @param class_name fully qualified class name, e.g. java.lang.String
    36       */
    37      public ObjectType(String class_name) {
    38          super(Constants.T_REFERENCE, "L" + class_name.replace('.', '/') + ";");
    39          this.class_name = class_name.replace('/', '.');
    40      }
    41
    42
    43      /*** @return name of referenced class
    44       */
    45      public String getClassName() {
    46          return class_name;
    47      }
    48
    49
    50      /*** @return a hash code value for the object.
    51       */
    52      public int hashCode() {
    53          return class_name.hashCode();
    54      }
    55
    56
    57      /*** @return true if both type objects refer to the same class.
    58       */
    59      public boolean equals( Object type ) {
    60          return (type instanceof ObjectType)
    61                  ? ((ObjectType) type).class_name.equals(class_name)
    62                  : false;
    63      }
    64
    65
    66      /***
    67       * If "this" doesn't reference a class, it references an interface
    68       * or a non-existant entity.
    69       * @deprecated this method returns an inaccurate result
    70       *   if the class or interface referenced cannot
    71       *   be found: use referencesClassExact() instead
    72       */
    73      public boolean referencesClass() {
    74          try {
    75              JavaClass jc = Repository.lookupClass(class_name);
    76              return jc.isClass();
    77          } catch (ClassNotFoundException e) {
    78              return false;
    79          }
    80      }
    81
    82
    83      /***
    84       * If "this" doesn't reference an interface, it references a class
    85       * or a non-existant entity.
    86       * @deprecated this method returns an inaccurate result
    87       *   if the class or interface referenced cannot
    88       *   be found: use referencesInterfaceExact() instead
    89       */
    90      public boolean referencesInterface() {
    91          try {
    92              JavaClass jc = Repository.lookupClass(class_name);
    93              return !jc.isClass();
    94          } catch (ClassNotFoundException e) {
    95              return false;
    96          }
    97      }
    98
    99
    100     /***
    101      * Return true if this type references a class,
    102      * false if it references an interface.
    103      * @return true if the type references a class, false if
    104      *   it references an interface
    105      * @throws ClassNotFoundException if the class or interface
    106      *   referenced by this type can't be found
    107      */
    108     public boolean referencesClassExact() throws ClassNotFoundException {
    109         JavaClass jc = Repository.lookupClass(class_name);
    110         return jc.isClass();
    111     }
    112
    113
    114     /***
    115      * Return true if this type references an interface,
    116      * false if it references a class.
    117      * @return true if the type references an interface, false if
    118      *   it references a class
    119      * @throws ClassNotFoundException if the class or interface
    120      *   referenced by this type can't be found
    121      */
    122     public boolean referencesInterfaceExact() throws ClassNotFoundException {
    123         JavaClass jc = Repository.lookupClass(class_name);
    124         return !jc.isClass();
    125     }
    126
    127
    128     /***
    129      * Return true if this type is a subclass of given ObjectType.
    130      * @throws ClassNotFoundException if any of this class's superclasses
    131      *  can't be found
    132      */
    133     public boolean subclassOf( ObjectType superclass ) throws ClassNotFoundException {
    134         if (this.referencesInterface() || superclass.referencesInterface()) {
    135             return false;
    136         }
    137         return Repository.instanceOf(this.class_name, superclass.class_name);
    138     }
    139
    140
    141     /***
    142      * Java Virtual Machine Specification edition 2, ß 5.4.4 Access Control
    143      * @throws ClassNotFoundException if the class referenced by this type
    144      *   can't be found
    145      */
    146     public boolean accessibleTo( ObjectType accessor ) throws ClassNotFoundException {
    147         JavaClass jc = Repository.lookupClass(class_name);
    148         if (jc.isPublic()) {
    149             return true;
    150         } else {
    151             JavaClass acc = Repository.lookupClass(accessor.class_name);
    152             return acc.getPackageName().equals(jc.getPackageName());
    153         }
    154     }
    155 }