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1   /*
2    * reserved comment block
3    * DO NOT REMOVE OR ALTER!
4    */
5   package com.sun.org.apache.bcel.internal.classfile;
6   
7   /* ====================================================================
8    * The Apache Software License, Version 1.1
9    *
10   * Copyright (c) 2001 The Apache Software Foundation.  All rights
11   * reserved.
12   *
13   * Redistribution and use in source and binary forms, with or without
14   * modification, are permitted provided that the following conditions
15   * are met:
16   *
17   * 1. Redistributions of source code must retain the above copyright
18   *    notice, this list of conditions and the following disclaimer.
19   *
20   * 2. Redistributions in binary form must reproduce the above copyright
21   *    notice, this list of conditions and the following disclaimer in
22   *    the documentation and/or other materials provided with the
23   *    distribution.
24   *
25   * 3. The end-user documentation included with the redistribution,
26   *    if any, must include the following acknowledgment:
27   *       "This product includes software developed by the
28   *        Apache Software Foundation (http://www.apache.org/)."
29   *    Alternately, this acknowledgment may appear in the software itself,
30   *    if and wherever such third-party acknowledgments normally appear.
31   *
32   * 4. The names "Apache" and "Apache Software Foundation" and
33   *    "Apache BCEL" must not be used to endorse or promote products
34   *    derived from this software without prior written permission. For
35   *    written permission, please contact apache@apache.org.
36   *
37   * 5. Products derived from this software may not be called "Apache",
38   *    "Apache BCEL", nor may "Apache" appear in their name, without
39   *    prior written permission of the Apache Software Foundation.
40   *
41   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
42   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52   * SUCH DAMAGE.
53   * ====================================================================
54   *
55   * This software consists of voluntary contributions made by many
56   * individuals on behalf of the Apache Software Foundation.  For more
57   * information on the Apache Software Foundation, please see
58   * <http://www.apache.org/>.
59   */
60  import  com.sun.org.apache.bcel.internal.Constants;
61  import com.sun.org.apache.bcel.internal.generic.Type;
62  import java.io.*;
63  
64  /**
65   * This class represents the field info structure, i.e., the representation
66   * for a variable in the class. See JVM specification for details.
67   *
68   * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
69   */
70  public final class Field extends FieldOrMethod {
71    /**
72     * Initialize from another object. Note that both objects use the same
73     * references (shallow copy). Use clone() for a physical copy.
74     */
75    public Field(Field c) {
76      super(c);
77    }
78  
79    /**
80     * Construct object from file stream.
81     * @param file Input stream
82     */
83    Field(DataInputStream file, ConstantPool constant_pool)
84         throws IOException, ClassFormatException
85    {
86      super(file, constant_pool);
87    }
88  
89    /**
90     * @param access_flags Access rights of field
91     * @param name_index Points to field name in constant pool
92     * @param signature_index Points to encoded signature
93     * @param attributes Collection of attributes
94     * @param constant_pool Array of constants
95     */
96    public Field(int access_flags, int name_index, int signature_index,
97                 Attribute[] attributes, ConstantPool constant_pool)
98    {
99      super(access_flags, name_index, signature_index, attributes, constant_pool);
100   }
101 
102   /**
103    * Called by objects that are traversing the nodes of the tree implicitely
104    * defined by the contents of a Java class. I.e., the hierarchy of methods,
105    * fields, attributes, etc. spawns a tree of objects.
106    *
107    * @param v Visitor object
108    */
109   public void accept(Visitor v) {
110     v.visitField(this);
111   }
112 
113   /**
114    * @return constant value associated with this field (may be null)
115    */
116   public final ConstantValue getConstantValue() {
117     for(int i=0; i < attributes_count; i++)
118       if(attributes[i].getTag() == Constants.ATTR_CONSTANT_VALUE)
119         return (ConstantValue)attributes[i];
120 
121     return null;
122   }
123 
124   /**
125    * Return string representation close to declaration format,
126    * `public static final short MAX = 100', e.g..
127    *
128    * @return String representation of field, including the signature.
129    */
130   public final String toString() {
131     String name, signature, access; // Short cuts to constant pool
132 
133     // Get names from constant pool
134     access    = Utility.accessToString(access_flags);
135     access    = access.equals("")? "" : (access + " ");
136     signature = Utility.signatureToString(getSignature());
137     name      = getName();
138 
139     StringBuffer  buf = new StringBuffer(access + signature + " " + name);
140     ConstantValue cv  = getConstantValue();
141 
142     if(cv != null)
143       buf.append(" = " + cv);
144 
145     for(int i=0; i < attributes_count; i++) {
146       Attribute a = attributes[i];
147 
148       if(!(a instanceof ConstantValue))
149         buf.append(" [" + a.toString() + "]");
150     }
151 
152     return buf.toString();
153   }
154 
155   /**
156    * @return deep copy of this field
157    */
158   public final Field copy(ConstantPool constant_pool) {
159     return (Field)copy_(constant_pool);
160   }
161 
162   /**
163    * @return type of field
164    */
165   public Type getType() {
166     return Type.getReturnType(getSignature());
167   }
168 }