BigDecimal君

import java.math.BigDecimal;

public class Test {
public static void main(String[] args) {

try{
System.out.println(new BigDecimal(302).divide(new BigDecimal(3)));
}catch(Exception e){
System.out.println("error!");
}

System.out.println(new BigDecimal(302).divide(new
BigDecimal(3), 6, BigDecimal.ROUND_UP));
System.out.println(new BigDecimal(302).divide(new
BigDecimal(3), 6, BigDecimal.ROUND_DOWN));
System.out.println(new BigDecimal(302).divide(new
BigDecimal(3), 6, BigDecimal.ROUND_HALF_UP));
}
}

↓

error!
100.666667
100.666666
100.666667