how do you connect if statements with different output using JOptionPane.showMessageDialog..here is my code: can someone help me fix it. I need to prompt user to put different year and month and display should tell user how many days does the certain month has.
PLEASE HELP ASAP:
CODE:
import javax.swing.JOptionPane;

public class mhalil3_h2_p2 {
public static void main (String[] args){


String yearString = JOptionPane.showInputDialog("Enter a year");
/*convert a string year into a int value*/
int year = Integer.parseInt(yearString);

/*declare variable month*/
String monthString = JOptionPane.showInputDialog ("Enter a month");
/*convert a string month into a int value*/
int month = Integer.parseInt (monthString);

/*boolean expression for the leap year and # of days in a month*/
if (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0){
System.out.println ("29 days");
}
else
{
System.out.println("28 days");
}
/*declare variable output*/
String output = (null,year + "is a leap year?" + isLeapYear );
/*Display the result*/
JOptionPane.showMessageDialog (null, output);

}
}

Google is your best friend

I Googled for JoptionPane JradioButton

and this is what I got.... can easily be stripped down for onlu display Km to Miles or Miles to KM

[code]
import javax.swing.*;
import javax.swing.JOptionPane; import java.awt.*;
import java.awt.event.*;
import java.util.StringTokenizer;

public class JOptionPaneDemo extends JFrame implements ActionListener {

Container contentPane = null;
private JButton jbnDialog;
String ButtonLabels;
private JRadioButton[] dialogTypeButtons;
private JRadioButton[] messageTypeButtons;
private int[] messageTypes = { JOptionPane.PLAIN_MESSAGE,
JOptionPane.INFORMATION_MESSAGE, JOptionPane.QUESTION_MESSAGE,
JOptionPane.WARNING_MESSAGE, JOptionPane.ERROR_MESSAGE };
private ButtonGroup messageTypeButtonGroup, buttonTypeButtonGroup,
dialogTypeButtonGroup;
private JRadioButton[] optionTypeButtons;
private int[] OptionTypes = { JOptionPane.DEFAULT_OPTION,
JOptionPane.YES_NO_OPTION, JOptionPane.YES_NO_CANCEL_OPTION,
JOptionPane.OK_CANCEL_OPTION };
public static void main(String[] args) {
new JOptionPaneDemo();
}
public JOptionPaneDemo() {
super("JOptionPane Source Demo");
addWindowListener(new WindowListener());
contentPane = getContentPane();
contentPane.setLayout(new GridLayout(0, 1));
JPanel jplButton = new JPanel();
jbnDialog = new JButton("Show an Option Pane");
jbnDialog.addActionListener(this);
jplButton.add(jbnDialog);
contentPane.add(jplButton);
createRadioButtonGroupings();
ButtonLabels = "Button1 Button2 Button3";
pack();
setVisible(true);
}
public void createRadioButtonGroupings() {
JPanel jplDialogType = new JPanel();
dialogTypeButtonGroup = new ButtonGroup();
dialogTypeButtons = new JRadioButton[] {
new JRadioButton("Show Message", true),
new JRadioButton("Get Confirmation"),
new JRadioButton("Collect Input"),
new JRadioButton("Present Options") };
for (int i = 0; i < dialogTypeButtons.length; i++) {
dialogTypeButtonGroup.add(dialogTypeButtons[i]);
jplDialogType.add(dialogTypeButtons[i]);
}
contentPane.add(jplDialogType);
JPanel jplMessageType = new JPanel();
messageTypeButtonGroup = new ButtonGroup();
messageTypeButtons = new JRadioButton[] {
new JRadioButton("Plain"),
new JRadioButton("Information", true),
new JRadioButton("Question"), new JRadioButton("Warning"),
new JRadioButton("Error") };
for (int i = 0; i < messageTypeButtons.length; i++) {
messageTypeButtonGroup.add(messageTypeButtons[i]);
jplMessageType.add(messageTypeButtons[i]);
}
contentPane.add(jplMessageType);
JPanel jplButtonType = new JPanel();
buttonTypeButtonGroup = new ButtonGroup();
optionTypeButtons = new JRadioButton[] {
new JRadioButton("Default", true),
new JRadioButton("Yes/No"),
new JRadioButton("Yes/No/Cancel"),
new JRadioButton("OK/Cancel") };
for (int i = 0; i < optionTypeButtons.length; i++) {
buttonTypeButtonGroup.add(optionTypeButtons[i]);
jplButtonType.add(optionTypeButtons[i]);
}
contentPane.add(jplButtonType);
}
// Windows Listener for Window Closing
public class WindowListener extends WindowAdapter {

public void windowClosing(WindowEvent event) {
System.exit(0);
}
}
public void actionPerformed(ActionEvent event) {
/*
* dialogTypeButtons =
*
* new JRadioButton[] { new JRadioButton("Show Message", true),
*
* new JRadioButton("Get Confirmation"),
*
* new JRadioButton("Collect Input"),
*
* new JRadioButton("Present Options") };
*/
if (dialogTypeButtons[0].isSelected()) {
JOptionPane.showMessageDialog(this, "Show Message",
"Simple Dialog", getMessageType());
} else if (dialogTypeButtons[1].isSelected()) {
JOptionPane.showConfirmDialog(this, "Get Confirmation",
"Simple Dialog", getButtonType(), getMessageType());
} else if (dialogTypeButtons[2].isSelected()) {
JOptionPane.showInputDialog(this, "Collect Input",
"Simple Dialog", getMessageType(), null, null, null);
} else if (dialogTypeButtons[3].isSelected()) {
JOptionPane.showOptionDialog(this, "Present Options",
"Simple Dialog", getButtonType(), getMessageType(),
null, substrings(ButtonLabels), null);
}
}
private int getAssociatedType(AbstractButton[] buttons, int[] types) {
for (int i = 0; i < buttons.length; i++) {
if (buttons[i].isSelected()) {
return (types[i]);
}
}
return (types[0]);
}
private int getMessageType() {
return (getAssociatedType(messageTypeButtons, messageTypes));
}
private int getButtonType() {
return (getAssociatedType(optionTypeButtons, OptionTypes));
}
private String[] substrings(String string) {
StringTokenizer tok = new StringTokenizer(string);
String[] substrings = new String[tok.countTokens()];
for (int i = 0; i < substrings.length; i++)
substrings[i] = tok.nextToken();
return (substrings);
}
}
/code]