Java將byte[]和int的互相轉換

/**
 * 將整數轉換為byte數組並指定長度
 * @param a 整數
 * @param length 指定長度
 * @return
 */
public static byte[] intToBytes(int a, int length) {
    byte[] bs = new byte[length];
    for (int i = bs.length - 1; i >= 0; i--) {
        bs[i] = (byte) (a % 255);
        a = a / 255;
    }
    return bs;
}

/**
 * 將byte數組轉換為整數
 * @param bs
 * @return
 */
public static int bytesToInt(byte[] bs) {
    int a = 0;
    for (int i = bs.length - 1; i >= 0; i--) {
        a += bs[i] * Math.pow(255, bs.length - i - 1);
    }
    return a;
}