HexUtil.java

/*
 * myLib - https://github.com/taktod/myLib
 * Copyright (c) 2014 ttProject. All rights reserved.
 * 
 * Licensed under The MIT license.
 */
package com.ttProject.util;

import java.nio.ByteBuffer;

/**
 * dump hex status.
 * from flazr.
 * @author taktod
 */
public class HexUtil {
	private static final char[] HEX_DIGITS = {
		'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
	};
	
	private static final char SEPARATOR = ' ';
	
	public static String toHex(final byte[] ba) {
		return toHex(ba, false);
	}
	public static String toHex(final byte[] ba, final boolean withSeparator) {
		return toHex(ba, 0, ba.length, withSeparator);
	}
	public static String toHex(final byte[] ba, final int offset, final int length, final boolean withSeparator) {
		final char[] buf;
		buf = new char[length * (withSeparator ? 3 : 2)];
		for(int i = offset, j = 0;i < offset + length;) {
			final char[] chars = toHexChars(ba[i ++]);
			buf[j ++] = chars[0];
			buf[j ++] = chars[1];
			if(withSeparator) {
				buf[j ++] = SEPARATOR;
			}
		}
		return new String(buf);
	}
	private static char[] toHexChars(final int b) {
		final char left = HEX_DIGITS[(b >>> 4) & 0x0F];
		final char right = HEX_DIGITS[b & 0x0F];
		return new char[] {left, right};
	}
	public static String toHex(final byte b) {
		final char[] chars = toHexChars(b);
		return String.valueOf(chars);
	}
	public static String toHex(final ByteBuffer buffer) {
		return toHex(buffer, false);
	}
	public static String toHex(final ByteBuffer buffer, final boolean withSeparator) {
		return toHex(buffer, 0, buffer.remaining(), withSeparator);
	}
	public static String toHex(final ByteBuffer buffer, final int offset, final int length, final boolean withSeparator) {
		int position = buffer.position();
		byte[] data = new byte[buffer.remaining()];
		buffer.get(data);
		buffer.position(position);
		return toHex(data, offset, length, withSeparator);
	}
	/**
	 * make byteBuffer from hexstrings.
	 * @return
	 */
	public static ByteBuffer makeBuffer(String hexString) {
		String target = hexString;
		ByteBuffer buffer = ByteBuffer.allocate(target.length() / 2);
		while(target.length() > 0) {
			String xStr = target.substring(0, 2);
			target = target.substring(2);
			buffer.put((byte)Integer.parseInt(xStr, 16));
		}
		buffer.flip();
		return buffer;
	}
}