將整數轉換為對應的8位二進制字符串

/**
* 將整數轉換為對應的8位二進制字符串
*/
public static String binaryString(int num) {
    StringBuilder result = new StringBuilder();
    int flag = 1 << 7;
    for (int i = 0; i < 8; i++) {
        int val = (flag & num) == 0 ? 0 : 1;
        result.append(val);
        num <<= 1;
    }
    return result.toString();
}