ByteUtil.java

package org.opencloudb.util;

import java.nio.charset.Charset;

public class ByteUtil {

	/**
	 * compare to 'number' array, for number :123456 ,store to array
	 * [1,2,3,4,5,6]
	 * 
	 * @param b1
	 * @param b2
	 * @return -1 means b1 < b2, or 0 means b1=b2 else return 1
	 */
	public static int compareNumberArray(byte[] b1, byte[] b2) {
		if (b1.length > b2.length) {
			return 1;
		} else if (b1.length < b2.length) {
			return -1;
		} else {
			for (int i = 0; i < b1.length; i++) {
				if (b1[i] > b2[i]) {
					return 1;
				} else if (b1[i] < b2[i]) {
					return -1;
				}

			}
		}
		return 0;
	}

	public static byte[] compareNumberArray2(byte[] b1, byte[] b2, int order) {
		if (b1.length <= 0 && b2.length > 0) {
			return b2;
		}
		if (b1.length > 0 && b2.length <= 0) {
			return b1;
		}
		int len = b1.length > b2.length ? b1.length : b2.length;
		for (int i = 0; i < len; i++) {
			if (b1[i] != b2[i])
				if (order == 1)
					return ((b1[i] & 0xff) - (b2[i] & 0xff)) > 0 ? b1 : b2;
				else
					return ((b1[i] & 0xff) - (b2[i] & 0xff)) > 0 ? b2 : b1;
		}

		return b1;
	}

	public static byte[] getBytes(short data) {
		byte[] bytes = new byte[2];
		bytes[0] = (byte) (data & 0xff);
		bytes[1] = (byte) ((data & 0xff00) >> 8);
		return bytes;
	}
	
	public static byte[] getBytes(char data) {
		byte[] bytes = new byte[2];
		bytes[0] = (byte) (data);
		bytes[1] = (byte) (data >> 8);
		return bytes;
	}

	public static byte[] getBytes(int data) {
		byte[] bytes = new byte[4];
		bytes[0] = (byte) (data & 0xff);
		bytes[1] = (byte) ((data & 0xff00) >> 8);
		bytes[2] = (byte) ((data & 0xff0000) >> 16);
		bytes[3] = (byte) ((data & 0xff000000) >> 24);
		return bytes;
	}

	public static byte[] getBytes(long data) {
		byte[] bytes = new byte[8];
		bytes[0] = (byte) (data & 0xff);
		bytes[1] = (byte) ((data >> 8) & 0xff);
		bytes[2] = (byte) ((data >> 16) & 0xff);
		bytes[3] = (byte) ((data >> 24) & 0xff);
		bytes[4] = (byte) ((data >> 32) & 0xff);
		bytes[5] = (byte) ((data >> 40) & 0xff);
		bytes[6] = (byte) ((data >> 48) & 0xff);
		bytes[7] = (byte) ((data >> 56) & 0xff);
		return bytes;
	}

	public static byte[] getBytes(float data) {
		int intBits = Float.floatToIntBits(data);
		return getBytes(intBits);
	}

	public static byte[] getBytes(double data) {
		long intBits = Double.doubleToLongBits(data);
		return getBytes(intBits);
	}

	public static byte[] getBytes(String data, String charsetName) {
		Charset charset = Charset.forName(charsetName);
		return data.getBytes(charset);
	}

	public static byte[] getBytes(String data) {
		return getBytes(data, "GBK");
	}

	public static short getShort(byte[] bytes) {
		return (short) ((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
	}

	public static char getChar(byte[] bytes) {
		return (char) ((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
	}

	public static int getInt(byte[] bytes) {
		return Integer.parseInt(new String(bytes));
		// return (0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)) | (0xff0000 &
		// (bytes[2] << 16)) | (0xff000000 & (bytes[3] << 24));
	}

	public static long getLong(byte[] bytes) {
		return Long.parseLong(new String(bytes));
		// return(0xffL & (long)bytes[0]) | (0xff00L & ((long)bytes[1] << 8)) |
		// (0xff0000L & ((long)bytes[2] << 16)) | (0xff000000L & ((long)bytes[3]
		// << 24))
		// | (0xff00000000L & ((long)bytes[4] << 32)) | (0xff0000000000L &
		// ((long)bytes[5] << 40)) | (0xff000000000000L & ((long)bytes[6] <<
		// 48)) | (0xff00000000000000L & ((long)bytes[7] << 56));
	}

	public static float getFloat(byte[] bytes) {
		return Float.intBitsToFloat(getInt(bytes));
	}

	public static double getDouble(byte[] bytes) {
		long l = getLong(bytes);
		return Double.longBitsToDouble(l);
	}

	public static String getString(byte[] bytes, String charsetName) {
		return new String(bytes, Charset.forName(charsetName));
	}

	public static String getString(byte[] bytes) {
		return getString(bytes, "GBK");

	}

	public static String getDate(byte[] bytes) {
		return new String(bytes);
	}

	public static String getTimestmap(byte[] bytes) {
		return new String(bytes);
	}

}