accessflags.java

已经移植好的java虚拟机

/*
 *  Copyright (c) 2000 Sun Microsystems, Inc., 901 San Antonio Road,
 *  Palo Alto, CA 94303, U.S.A.  All Rights Reserved.
 *
 *  Sun Microsystems, Inc. has intellectual property rights relating
 *  to the technology embodied in this software.  In particular, and
 *  without limitation, these intellectual property rights may include
 *  one or more U.S. patents, foreign patents, or pending
 *  applications.  Sun, Sun Microsystems, the Sun logo, Java, KJava,
 *  and all Sun-based and Java-based marks are trademarks or
 *  registered trademarks of Sun Microsystems, Inc.  in the United
 *  States and other countries.
 *
 *  This software is distributed under licenses restricting its use,
 *  copying, distribution, and decompilation.  No part of this
 *  software may be reproduced in any form by any means without prior
 *  written authorization of Sun and its licensors, if any.
 *
 *  FEDERAL ACQUISITIONS:  Commercial Software -- Government Users
 *  Subject to Standard License Terms and Conditions
 */
package kdp.classparser;

import java.io.*;

/**
 * Encapsulates the access flags for a class file.
 *
 * @author 			Aaron Dietrich
 * @version			$Id: AccessFlags.java,v 1.1.1.1 2000/07/07 13:34:23 jrv Exp $
 *
 * Revision History
 *   $Log: AccessFlags.java,v $
 *   Revision 1.1.1.1  2000/07/07 13:34:23  jrv
 *   Initial import of kdp code
 *
 *   Revision 1.1.1.1  2000/05/31 19:14:47  ritsun
 *   Initial import of kvmdt to CVS
 *
 *   Revision 1.1  2000/04/25 00:36:43  ritsun
 *   Initial revision
 *
 */
public class AccessFlags
  {
   /** access flag if this class is public */
   private static final int		ACC_PUBLIC    	= 0x0001;
   /** access flag if this class is final */
   private static final int		ACC_FINAL     	= 0x0010;
   /** access flag if this class is "super" */
   private static final int		ACC_SUPER		= 0x0020;
   /** access flag if this class is an interface */
   private static final int		ACC_INTERFACE	= 0x0200;
   /** access flag if this class is abstract */
   private static final int		ACC_ABSTRACT	= 0x0400;
   /** access flag if this class is an Array class  */
   private static final int		ACC_ARRAY	= 0x1000;

   /** access permissions to and properties of this class */
   private int 				flags;

   /**
    * Constructor.  Reads the access flags from the
    * specified DataInputStream.
    *
    * @param		iStream			input stream attached
    *						    	to the class file
    */
   public AccessFlags (DataInputStream iStream) throws IOException
     {
      flags = iStream.readUnsignedShort ();
     }

   /**
    * Converts the access flags to an easy to read format
    *
    * @return		String			string representation
    *							of the access flags
    */
   public String toString ()
     {
      String			s = new String ("Class Access Flags:\t");

      //just go through all the possibilities and build a string
      //of the access flags
      if ((flags & ACC_PUBLIC) > 0)
        s = s + "public ";

      if ((flags & ACC_FINAL) > 0)
        s = s + "final ";

      if ((flags & ACC_SUPER) > 0)
        s = s + "super ";

      if ((flags & ACC_INTERFACE) > 0)
        s = s + "interface ";

      if ((flags & ACC_ABSTRACT) > 0)
        s = s + "abstract";

      return s;
     }

    public byte getJDWPTypeTag() {
	if ((flags & ACC_ARRAY) > 0)
		return 3;
	else if ((flags & ACC_INTERFACE) > 0)
		return 2;
	else
		return 1;
    }

    public int getRawAccessFlags() {
	return (flags);
    }
  }