bytearraybytestream.java

冒险岛私服Java版服务端(Odinms)源代码。学习JAVA开发的朋友

/*
	This file is part of the OdinMS Maple Story Server
    Copyright (C) 2008 Patrick Huy <[e-mail]> 
                       Matthias Butz <[e-mail]>
                       Jan Christian Meyer <[e-mail]>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License version 3
    as published by the Free Software Foundation. You may not use, modify
    or distribute this program under any other version of the
    GNU Affero General Public License.

    This program 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package net.sf.odinms.tools.data.input;

import java.io.IOException;

import net.sf.odinms.tools.HexTool;

/**
 * Provides for an abstraction layer for an array of bytes.
 * 
 * @author Frz
 * @version 1.0
 * @since Revision 326
 */
public class ByteArrayByteStream implements SeekableInputStreamBytestream {
	private int pos = 0;
	private long bytesRead = 0;
	private byte[] arr;

	/**
	 * Class constructor.
	 * 
	 * @param arr Array of bytes to wrap the stream around.
	 */
	public ByteArrayByteStream(byte[] arr) {
		this.arr = arr;
	}

	/**
	 * Gets the current position of the stream.
	 * 
	 * @return The current position of the stream.
	 * @see net.sf.odinms.tools.data.input.SeekableInputStreamBytestream#getPosition()
	 */
	@Override
	public long getPosition() {
		return pos;
	}

	/**
	 * Seeks the pointer the the specified position.
	 * 
	 * @param offset The position you wish to seek to.
	 * @see net.sf.odinms.tools.data.input.SeekableInputStreamBytestream#seek(long)
	 */
	@Override
	public void seek(long offset) throws IOException {
		pos = (int) offset;
	}

	/**
	 * Returns the numbers of bytes read from the stream.
	 * 
	 * @return The number of bytes read.
	 * @see net.sf.odinms.tools.data.input.ByteInputStream#getBytesRead()
	 */
	@Override
	public long getBytesRead() {
		return bytesRead;
	}

	/**
	 * Reads a byte from the current position.
	 * 
	 * @return The byte as an integer.
	 * @see net.sf.odinms.tools.data.input.ByteInputStream#readByte()
	 */
	@Override
	public int readByte() {
		bytesRead++;
		return ((int) arr[pos++]) & 0xFF;
	}

	/**
	 * Returns the current stream as a hexadecimal string of values.
	 * Shows the entire stream, and the remaining data at the current position.
	 * 
	 * @return The current stream as a string.
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		String nows = "";
		if (arr.length - pos > 0) {
			byte[] now = new byte[arr.length - pos];
			System.arraycopy(arr, pos, now, 0, arr.length - pos);
			nows = HexTool.toString(now);
		}
		return "All: " + HexTool.toString(arr) + "\nNow: " + nows;
	}

	/**
	 * Returns the number of bytes available from the stream.
	 * 
	 * @return Number of bytes available as a long integer.
	 * @see net.sf.odinms.tools.data.input.ByteInputStream#available()
	 */
	@Override
	public long available() {
		return arr.length - pos;
	}
}