JOptionPane is a easy way to do dialog boxes, messages or inputs.
You have to import it at the beginning of the program:

import javax.swing.JOptionPane;

The arguments for JOptionPane:

for a simple message box:

JOptionPane.showMessageDialog (
null, “Put your message here” );to show text in different rows:

JOptionPane.showMessageDialog (
null, “Put \nyour \nmessage \nhere” );

the \n switches to next line

Sample program:

//A sample program.
import javax.swing.JOptionPane; // imports JOptionPane classpublic class Sample {
public static void main ( String args[] )
JOptionPane.showMessageDialog (
null, “This is a sample program” );

System.exit ( 0 ); //stops the program

To show different messages with different icons, you’ll need 4 arguments instead of 2.

JOptionPane.showMessageDialog (
null, “Messagehere”, “Title here”, JOptionPane.PLAIN_MESSAGE);

There are different kinds of icons for a dialog box, just replace the last argument:

JOptionPane.PLAIN_MESSAGE // this is a plain message
JOptionPane.INFORMATION_MESSAGE // this is a info message
JOptionPane.ERROR_MESSAGE // this is a error message
JOptionPane.WARNING_MESSAGE // this is a warning message

You can also use JOptionPane for dialog boxes for input, and assign them to variables, just put:

name=   // The variable
JOptionPane.showInputDialog ( “put your message here” );

note: after using JOptionPane, dont forget to exit System.exit

Sample Program:

// An addition programimport javax.swing.JOptionPane; //import class JOptionPane

public class Addition {
public static void main ( String args[] )
String firstNumber, //first string entered by user
secondNumber; // second string entered by user

int number1,     // first number to add
number2,    //second number to add
sum;                //sum of number1 and number2

//read in the first number from user as a string
firstNumber =
JOptionPane.showInputDialog ( “Enter first integer” );

//read in the second number from user as a string
secondNumber =
JOptionPane.showInputDialog ( “Enter second interger” );

//convert numbers from type String to type int
number1 = Integer.parseInt ( firstNumber);
number2 = Integer.parseInt ( secondNumber);

//add the numbers
sum = number1 + number2;

//display the results
JOptionPane.showMessageDialog (
null, “The sum is ” + sum, “Results”,
System.exit ( 0 ); //ends the program

JOptionPane can ONLY be used to input string, so if you want to use numbers, you have to create separate variables to change it into integers, or real numbers.