ConstantCP 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.classfile;
    18
    19  import java.io.DataInputStream;
    20  import java.io.DataOutputStream;
    21  import java.io.IOException;
    22  import org.apache.bcel.Constants;
    23
    24  /***
    25   * Abstract super class for Fieldref and Methodref constants.
    26   *
    27   * @version $Id: ConstantCP.java 386056 2006-03-15 11:31:56Z tcurdt $
    28   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    29   * @see     ConstantFieldref
    30   * @see     ConstantMethodref
    31   * @see     ConstantInterfaceMethodref
    32   */
    33  public abstract class ConstantCP extends Constant {
    34
    35      /*** References to the constants containing the class and the field signature
    36       */
    37      protected int class_index, name_and_type_index;
    38
    39
    40      /***
    41       * Initialize from another object.
    42       */
    43      public ConstantCP(ConstantCP c) {
    44          this(c.getTag(), c.getClassIndex(), c.getNameAndTypeIndex());
    45      }
    46
    47
    48      /***
    49       * Initialize instance from file data.
    50       *
    51       * @param tag  Constant type tag
    52       * @param file Input stream
    53       * @throws IOException
    54       */
    55      ConstantCP(byte tag, DataInputStream file) throws IOException {
    56          this(tag, file.readUnsignedShort(), file.readUnsignedShort());
    57      }
    58
    59
    60      /***
    61       * @param class_index Reference to the class containing the field
    62       * @param name_and_type_index and the field signature
    63       */
    64      protected ConstantCP(byte tag, int class_index, int name_and_type_index) {
    65          super(tag);
    66          this.class_index = class_index;
    67          this.name_and_type_index = name_and_type_index;
    68      }
    69
    70
    71      /***
    72       * Dump constant field reference to file stream in binary format.
    73       *
    74       * @param file Output file stream
    75       * @throws IOException
    76       */
    77      public final void dump( DataOutputStream file ) throws IOException {
    78          file.writeByte(tag);
    79          file.writeShort(class_index);
    80          file.writeShort(name_and_type_index);
    81      }
    82
    83
    84      /***
    85       * @return Reference (index) to class this field or method belongs to.
    86       */
    87      public final int getClassIndex() {
    88          return class_index;
    89      }
    90
    91
    92      /***
    93       * @return Reference (index) to signature of the field.
    94       */
    95      public final int getNameAndTypeIndex() {
    96          return name_and_type_index;
    97      }
    98
    99
    100     /***
    101      * @param class_index points to Constant_class
    102      */
    103     public final void setClassIndex( int class_index ) {
    104         this.class_index = class_index;
    105     }
    106
    107
    108     /***
    109      * @return Class this field belongs to.
    110      */
    111     public String getClass( ConstantPool cp ) {
    112         return cp.constantToString(class_index, Constants.CONSTANT_Class);
    113     }
    114
    115
    116     /***
    117      * @param name_and_type_index points to Constant_NameAndType
    118      */
    119     public final void setNameAndTypeIndex( int name_and_type_index ) {
    120         this.name_and_type_index = name_and_type_index;
    121     }
    122
    123
    124     /***
    125      * @return String representation.
    126      */
    127     public final String toString() {
    128         return super.toString() + "(class_index = " + class_index + ", name_and_type_index = "
    129                 + name_and_type_index + ")";
    130     }
    131 }