캐시백 계산 (테스트)

import java.util.Scanner;

public class JavaStudy02 {
private static MyScanner my;

public JavaStudy02() {
}

public static void main(String[] args) {
my = new MyScanner();
int cash = true;
System.out.println("[캐시백 계산]");
int cash = my.getScannerReturnInt("결제 금액을 입력해 주세요.(금액):");
my.close();
int cashBack = (int)((double)cash * 0.1) <= 300 ? 300 : (int)((double)cash * 0.1) / 100 * 100;
System.out.println(String.format("결제 금액은 %d원이고, 캐시백은 %d원 입니다.", cash, cashBack));
}

static class MyScanner {
Scanner scan;

MyScanner() {
this.scan = new Scanner(System.in);
}

public int getScannerReturnInt(String text) {
while(true) {
System.out.print(text);
String str = this.scan.nextLine();
if (str.matches("[0-9]+")) {
return Integer.parseInt(str);
}

System.out.println("잘못된 입력입니다. 숫자 값을 입력해주세요.");
}
}

public void close() {
this.scan.close();
}
}
}