16進数（Byte）から2進数の文字列を得る

Bin.groovy

class Bin {
    Integer maxBit = 8
    Byte b
    String binaryString
    String latestPaddingPrefix
    
    
    static of (Integer b) {
        new Bin(b as Byte)
    }
    
    private Bin(Byte b) {
        this.b = b
        binaryString = toBinaryString(b)
        latestPaddingPrefix = '0'
    }
    
    def shiftL(Integer operand) {
        b = b << operand
        binaryString = toBinaryString(b)
        latestPaddingPrefix = '0'
        this
    }
    
    def shiftR(Integer operand) {
        b = b >> operand
        binaryString = toBinaryString(b)
        latestPaddingPrefix = binaryString[0] == '1' ? '1' : '0'
        this
    }
    
    String toBinaryString(Byte b) {
        Integer.toBinaryString(b)
    }
    
    String normalize() {
        if (binaryString.length() > maxBit) {
            binaryString[-maxBit..-1]
        } else {
            binaryString.padLeft(maxBit, latestPaddingPrefix)
        }
    }
}

assert "00010101" == Bin.of(0x15).normalize()
assert "00101010" == Bin.of(0x15).shiftL(1).normalize()
assert "01010100" == Bin.of(0x15).shiftL(2).normalize()

assert "10100011" == Bin.of(0xA3).normalize()
assert "11010001" == Bin.of(0xA3).shiftR(1).normalize()
assert "11101000" == Bin.of(0xA3).shiftR(2).normalize()