[Tutorial] JOptionPane: easy input, output with dialog boxes

[Paul]

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

Java:

import javax.swing.JOptionPane;

The arguments for JOptionPane:

for a simple message box:

Java:

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:

Java:

//A sample program. Sample.java import javax.swing.JOptionPane; // imports JOptionPane class public 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.

Java:

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

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

Java:

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:

Java:

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

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

Sample Program:

Java:

// Addition.java // An addition program import 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", JOptionPane.PLAIN_MESSAGE); System.exit ( 0 ); //ends the program } }

NOTE:
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.

PS: I'll add more if needed, if you don't know the parse.Int part, thats ok, as long as you get the main idea of JOptionPane. These may not work 100%, feed back pls.[/b]

[Tony]

nice And this is soo much simpler then setting up input buffers and exseption handlers for basic cin>> Might be using this on CCC if they'll have any questions with manual input

+50Bits

[the_short1]

very nice.. i already learned this. .but its a very good tut. . heres 5bits :d