常見數字類型long, int, short和byte數組的轉換

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/**
 * 常見數字類型和byte數組的互相轉換
 * @author ERic
 *
 */
public class BytesHelper {

	public static byte[] longToByte(long number) {
		long temp = number;
		byte[] b = new byte[8];
		for (int i = 0; i < b.length; i++) {
			b[i] = new Long(temp & 0xff).byteValue();
			temp = temp >> 8;
		}
		return b;
	}

	public static long byteToLong(byte[] b) {
		long s = 0;
		//最低位
		long s0 = b[0] & 0xff;
		long s1 = b[1] & 0xff;
		long s2 = b[2] & 0xff;
		long s3 = b[3] & 0xff;
		long s4 = b[4] & 0xff;
		long s5 = b[5] & 0xff;
		long s6 = b[6] & 0xff;
		long s7 = b[7] & 0xff;
		s1 <<= 8;
		s2 <<= 16;
		s3 <<= 24;
		s4 <<= 8 * 4;
		s5 <<= 8 * 5;
		s6 <<= 8 * 6;
		s7 <<= 8 * 7;
		s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;
		return s;
	}

	public static byte[] intToByte(int number) {
		int temp = number;
		byte[] b = new byte[4];
		for (int i = 0; i < b.length; i++) {
			b[i] = new Integer(temp & 0xff).byteValue();
			temp = temp >> 8;
		}
		return b;
	}

	public static int byteToInt(byte[] b) {
		int s = 0;
		int s0 = b[0] & 0xff;
		int s1 = b[1] & 0xff;
		int s2 = b[2] & 0xff;
		int s3 = b[3] & 0xff;
		s3 <<= 24;
		s2 <<= 16;
		s1 <<= 8;
		s = s0 | s1 | s2 | s3;
		return s;
	}

	public static byte[] shortToByte(short number) {
		int temp = number;
		byte[] b = new byte[2];
		for (int i = 0; i < b.length; i++) {
			b[i] = new Integer(temp & 0xff).byteValue();
			temp = temp >> 8;
		}
		return b;
	}

	public static short byteToShort(byte[] b) {
		short s = 0;
		short s0 = (short) (b[0] & 0xff);// 最低位
		short s1 = (short) (b[1] & 0xff);
		s1 <<= 8;
		s = (short) (s0 | s1);
		return s;
	}
}