/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
package com.sun.org.apache.bcel.internal.classfile;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import  com.sun.org.apache.bcel.internal.Constants;
import  java.io.*;

/**
 * This class is derived from the abstract
 * <A HREF="com.sun.org.apache.bcel.internal.classfile.Constant.html">Constant</A> class
 * and represents a reference to a String object.
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     Constant
 */
public final class ConstantString extends Constant implements ConstantObject {
  private int string_index; // Identical to ConstantClass except for this name

  /**
   * Initialize from another object.
   */
  public ConstantString(ConstantString c) {
    this(c.getStringIndex());
  }
  /**
   * Initialize instance from file data.
   *
   * @param file Input stream
   * @throws IOException
   */
  ConstantString(DataInputStream file) throws IOException
  {
    this((int)file.readUnsignedShort());
  }
  /**
   * @param string_index Index of Constant_Utf8 in constant pool
   */
  public ConstantString(int string_index)
  {
    super(Constants.CONSTANT_String);
    this.string_index = string_index;
  }
  /**
   * Called by objects that are traversing the nodes of the tree implicitely
   * defined by the contents of a Java class. I.e., the hierarchy of methods,
   * fields, attributes, etc. spawns a tree of objects.
   *
   * @param v Visitor object
   */
  public void accept(Visitor v) {
    v.visitConstantString(this);
  }
  /**
   * Dump constant field reference to file stream in binary format.
   *
   * @param file Output file stream
   * @throws IOException
   */
  public final void dump(DataOutputStream file) throws IOException
  {
    file.writeByte(tag);
    file.writeShort(string_index);
  }
  /**
   * @return Index in constant pool of the string (ConstantUtf8).
   */
  public final int getStringIndex() { return string_index; }
  /**
   * @param string_index.
   */
  public final void setStringIndex(int string_index) {
    this.string_index = string_index;
  }
  /**
   * @return String representation.
   */
  public final String toString()
  {
    return super.toString() + "(string_index = " + string_index + ")";
  }

  /** @return String object
   */
  public Object getConstantValue(ConstantPool cp) {
    Constant c = cp.getConstant(string_index, Constants.CONSTANT_Utf8);
    return ((ConstantUtf8)c).getBytes();
  }

  /** @return dereferenced string
   */
  public String getBytes(ConstantPool cp) {
    return (String)getConstantValue(cp);
  }
}
