package org.apache.bcel.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",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * 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  org.apache.bcel.Constants;
import org.apache.bcel.generic.Type;
import java.io.*;

/**
 * This class represents the field info structure, i.e., the representation 
 * for a variable in the class. See JVM specification for details.
 *
 * @version $Id: Field.java,v 1.3 2002/12/08 16:04:37 mdahm Exp $
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public final class Field extends FieldOrMethod {
  /**
	 * 
	 */
	private static final long serialVersionUID = -8818168458027904498L;

/**
   * Initialize from another object. Note that both objects use the same
   * references (shallow copy). Use clone() for a physical copy.
   */
  public Field(Field c) {
    super(c);
  }

  /**
   * Construct object from file stream.
   * @param file Input stream
   */
  Field(DataInputStream file, ConstantPool constant_pool)
       throws IOException, ClassFormatException
  {
    super(file, constant_pool);
  }

  /**
   * @param access_flags Access rights of field
   * @param name_index Points to field name in constant pool
   * @param signature_index Points to encoded signature
   * @param attributes Collection of attributes
   * @param constant_pool Array of constants
   */
  public Field(int access_flags, int name_index, int signature_index,
	       Attribute[] attributes, ConstantPool constant_pool)
  {
    super(access_flags, name_index, signature_index, attributes, constant_pool);
  }

  /**
   * 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.visitField(this);
  }

  /**
   * @return constant value associated with this field (may be null)
   */
  public final ConstantValue getConstantValue() {
    for(int i=0; i < attributes_count; i++)
      if(attributes[i].getTag() == Constants.ATTR_CONSTANT_VALUE)
	return (ConstantValue)attributes[i];

    return null;
  }

  /**
   * Return string representation close to declaration format,
   * `public static final short MAX = 100', e.g..
   *
   * @return String representation of field, including the signature.
   */
  public final String toString() {
    String name, signature, access; // Short cuts to constant pool

    // Get names from constant pool
    access    = Utility.accessToString(access_flags);
    access    = access.equals("")? "" : (access + " ");
    signature = Utility.signatureToString(getSignature());
    name      = getName();

    StringBuffer  buf = new StringBuffer(access + signature + " " + name);
    ConstantValue cv  = getConstantValue();

    if(cv != null)
      buf.append(" = " + cv);

    for(int i=0; i < attributes_count; i++) {
      Attribute a = attributes[i];

      if(!(a instanceof ConstantValue))
	buf.append(" [" + a.toString() + "]");
    }

    return buf.toString();
  }

  /**
   * @return deep copy of this field
   */
  public final Field copy(ConstantPool constant_pool) {
    return (Field)copy_(constant_pool);
  }

  /**
   * @return type of field
   */
  public Type getType() {
    return Type.getReturnType(getSignature());
  }
}