计算一个圆柱体的体积

import javax.swing.JOptionPane;
public class ComputeVolume {
    public static void main(String[] args){
        final double PI = 3.14;
        double volume;
        String inputRadius = JOptionPane.showInputDialog(null,"plz enter a radius:",
                "Input Dialog Demo",JOptionPane.QUESTION_MESSAGE);
        String inputHeight = JOptionPane.showInputDialog(null,"plz enter a height:",
                "Input Dialog Demo",JOptionPane.QUESTION_MESSAGE);
        double radius = Double.parseDouble(inputRadius);
        double height = Double.parseDouble(inputHeight);
        volume = (int)(radius * radius * PI * height);
        JOptionPane.showMessageDialog(null, "the Volume is :" + volume);
    }
}