/*

 * 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.

 *

 * 4. The names "Apache" and "Apache Software Foundation" and

 *    "Apache BCEL" must not be used to endorse or promote products

 *    derived from this software without prior written permission. For

 *    written permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

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 *    prior written permission of the Apache Software Foundation.

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 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * 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);

  }

}