Java數值轉化爲二進制、十進制、十六進制字符串

int i = 123;
String binStr = Integer.toBinaryString(i);
String otcStr = Integer.toOctalString(i);
String hexStr = Integer.toHexString(i);

String str = Integer.toBinaryString(i);
String reverseStr = new StringBuilder(str).reverse().toString();
if (reverseStr.charAt(0) == '1') {
　　System.out.println('True')
}