intreader.java

Java Communicating Agents是一个用于开发网络反应式信息agent的框架

/*
 * $Source: /home/data/cvsroot/src/jacomma/icm/io/imp/IntReader.java,v $
 * $Revision: 1.8 $
 * $Date: 2000/10/28 20:09:07 $
 *
 * This file is part of the jacomma framework
 * Copyright (c) 2000 	Dimitrios Vyzovitis
 *			mailto:[e-mail]
 *			
 *
 *			
 *			
 *			
 *
 *	This library is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU Library General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This library is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU Library General Public License for more details.
 *
 *	You should have received a copy of the GNU Library General Public License
 *	along with this library; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, 
 *	Boston, MA  02111-1307  USA
 */

package jacomma.icm.io.imp;

import jacomma.icm.io.EncObject;
import jacomma.icm.io.EncObjectType;
import jacomma.icm.io.EncObjectReader;

import jacomma.util.ByteArrayReader;

public class IntReader extends ReaderTemplate {

	byte[] number_;
	int state_;
	int length_;
	
	final static int HEAD = 0;
	final static int LENGTH_HEAD = 1;
	final static int LENGTH = 2;
	final static int BODY = 3;
	final static int DONE = 4;

	public IntReader(){}

	public void start( java.io.InputStream stream ) throws java.io.IOException {
		super.start( stream );
		
		state_ = HEAD;		
	}

	public void readNext() throws java.io.IOException {

		switch ( state_ ) {
		case HEAD: {
			if ( (length_ = readNextByte() & 0x0f) == 0x00 )
				state_ = LENGTH_HEAD;
			else
				state_ = BODY;
			break;
		} case LENGTH_HEAD: {
			if ( (length_ = readNextByte() & 0x0f) == 0x00 ) {
				number_ = new byte[]{(byte)0x00};
				state_ = DONE;
			} else
				state_ = LENGTH;
			break;
		} case LENGTH: {
			ByteArrayReader rd = null;
			for ( rd = new ByteArrayReader( length_, stream_ );
				  rd.hasNext();
				  rd.readNext() );
			length_ = IOUtilities.decodeLength( rd.toByteArray() );
			state_ = BODY;
			break;
		} case BODY: {
			ByteArrayReader rd = null;
			for ( rd = new ByteArrayReader( length_, stream_ );
				  rd.hasNext();
				  rd.readNext() );
			number_ = rd.toByteArray();
			state_ = DONE;
			break;
		} 
		default: return;
		}

		done_ = (state_ == DONE);

	}

	protected EncObject makeObject() {
		return new EncObjectImp( EncObjectType.Int, number_ );
	}

	public boolean canHandle( EncObjectType t ) {
		return EncObjectType.Int.equals( t );
	}
	
}