Hiya, I am using following Java file which creates a GUI, in the input field if i put any character why dont I see the JOptionPane.showMessageDialog pop up window as mentioned in the code?
Any clues?
Thx
Rony
//import statements
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.text.DecimalFormat;
/**
* Sediment Yield MUSLE
* Shahriar Shams
* class description
*/
public class SedimentYield1 extends JFrame implements ActionListener
{
double V, Qp, K, LS, C, P;
String outputSY;
boolean goodInput = true;
double SY;
JPanel SYPanelInput = new JPanel();
JPanel SYPanelCentre = new JPanel();
JPanel SYPanelOutput = new JPanel();
private JButton jbtCalculate = new JButton ("Calculate");
private JButton jbtClear = new JButton ("Clear");
//Input
JLabel Vlbl = new JLabel("Volume of Runoff in acre-ft, V");
JTextField Vtf = new JTextField(8);
JLabel Qplbl = new JLabel("Peak Flow per Storm Event in cfs, Qp");
JTextField Qptf = new JTextField(8);
JLabel Klbl = new JLabel("Soil Erodibility Factor, K");
JTextField Ktf = new JTextField(8);
JLabel LSlbl = new JLabel("Soil Loss Ratio, LS");
JTextField LStf = new JTextField(8);
JLabel Clbl = new JLabel("Cropping Factor, C");
JTextField Ctf = new JTextField(8);
JLabel Plbl = new JLabel("Practice Factor, P");
JTextField Ptf = new JTextField(8);
//ouput
JLabel SYlbl = new JLabel("Sediment Yield per storm in tons");
JTextField SYtf = new JTextField("Will be computed");
public SedimentYield1()
{
SYPanelInput.setLayout(new GridLayout(6,2));
SYPanelInput.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
SYPanelCentre.setLayout(new GridLayout(1,2));
SYPanelCentre.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
SYPanelOutput.setLayout(new GridLayout(1,2));
SYPanelOutput.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
//adding Components
SYPanelInput.add(Vlbl);
SYPanelInput.add(Vtf);
SYPanelInput.add(Qplbl);
SYPanelInput.add(Qptf);
SYPanelInput.add(Klbl);
SYPanelInput.add(Ktf);
SYPanelInput.add(LSlbl);
SYPanelInput.add(LStf);
SYPanelInput.add(Clbl);
SYPanelInput.add(Ctf);
SYPanelInput.add(Plbl);
SYPanelInput.add(Ptf);
//output added
SYPanelCentre.add(SYlbl);
SYPanelCentre.add(SYtf);
// adding buttons
SYPanelOutput.add(jbtCalculate);
jbtCalculate.addActionListener(this);
SYPanelOutput.add(jbtClear);
jbtClear.addActionListener(this);
String strV = Vtf.getText();
String strQp = Qptf.getText();
String strK = Ktf.getText();
String strLS = LStf.getText();
String strC = Ctf.getText();
String strP = Ptf.getText();
try
{
V = Double.parseDouble(strV);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
try
{
Qp = Double.parseDouble(strQp);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
try
{
K = Double.parseDouble(strK);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
try
{
LS = Double.parseDouble(strLS);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
try
{
C = Double.parseDouble(strC);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
try
{
P = Double.parseDouble(strP);
}
catch (NumberFormatException nfeDouble)
{
JOptionPane.showMessageDialog(null, "You need to enter a\nnumber", "Input Error", JOptionPane.ERROR_MESSAGE);
goodInput = false;
}
if (goodInput)
{
//Calculating Sediment Yield
SY = 95.0*(Math.pow((V*Qp),0.56))*K*LS*C*P;
//Create the format for the Celsius text field.
DecimalFormat twoDigits = new DecimalFormat("0.00");
outputSY = twoDigits.format(SY);
}
// JFrame.setDefaultLookAndFeelDecorated(true);
//2. Create the frame.
JFrame frame = new JFrame("Sedidement Yield from Watershed");
//3. Optional: What happens when the frame closes?
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//4. Create components and put them in the frame.
//...create emptyLabel...
frame.getContentPane().add(SYPanelInput, BorderLayout.NORTH);
frame.getContentPane().add(SYPanelCentre, BorderLayout.CENTER);
frame.getContentPane().add(SYPanelOutput, BorderLayout.SOUTH);
//5. Size the frame.
frame.setSize(new Dimension(500,280));
//6. Show it.
frame.setVisible(true);
}
public static void main(String[] args) {
SedimentYield SYframe = new SedimentYield();
}
public void actionPerformed(ActionEvent e) {
if (e.getSource()== jbtClear)
{
Vtf.setText("");
Qptf.setText("");
Ktf.setText("");
LStf.setText("");
Ctf.setText("");
Ptf.setText("");
SYtf.setText("Will be calculated");
}
if (e.getSource()== jbtCalculate)
{
System.out.println("Sediment Yield ="+outputSY);
SYtf.setText(outputSY);
}
}
}
Offline 
Unsolved 
