无法整除会报错
java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result.

用 BigDecimal(String val)  
 
BigDecimal bd = new BigDecimal("0.333");


        
import java.math.BigDecimal;
import java.math.RoundingMode;

public class BigDecimalTest {

    public static void main(String[] args) throws Exception {
        BigDecimal bd0 = new BigDecimal(1.0/3);
        System.out.println(bd0);
        
        bd0 = bd0.setScale(3, RoundingMode.HALF_UP);
        System.out.println(bd0);
        
        bd0 = new BigDecimal("0.333");
        System.out.println(bd0);
        
        bd0 = bd0.setScale(2, RoundingMode.HALF_UP);
        System.out.println(bd0);
        
        
        BigDecimal bd1 = new BigDecimal("1");
        BigDecimal bd2 = new BigDecimal("2");
        BigDecimal bd3 = bd1.divide(bd2);
        System.out.println(bd3);

        bd2 = new BigDecimal("3");
        bd3 = bd1.divide(bd2,3, RoundingMode.HALF_UP);
        System.out.println(bd3);

        // java.lang.ArithmeticException: Non-terminating decimal expansion; no exact
        // representable decimal result.
        try {
            bd2 = new BigDecimal("3");
            bd3 = bd1.divide(bd2);
            System.out.println(bd3);
        } catch (Throwable e) {
            System.out.println(e);
        }
    }
}