Program Description:
The program below is a simple java code arithmetic operation using JButton as arithmetic operator selector and JOptionPane as user input. It is also capable of catching number format error like putting non-integer numbers.
Output:
Code:
/**
* File: arithmeticOperationJOptionPane.java
* Tiltle: Arithmetic Operation using JOptionPane
* Author: http://java-code-complete.blogspot.com/
*/
//Java Core Package
import javax.swing.*;
//Java Extension Package
import java.awt.*;
import java.awt.event.*;
public class arithmeticOperationJOptionPane extends JFrame {
//Initializing JButton and String operation as the label of each JButton
private JButton buttons[];
private String operation[] = {"Addition [+]","Subtraction [-]","Multiplication [x]","Division [/]"};
//Setting up GUI
public arithmeticOperationJOptionPane() {
//Setting up the Title of the Window
super("Arithmetic Operation using JOptionPane");
//Set Size of the Window (WIDTH, HEIGHT)
setSize(320,120);
//Exit Property of the Window
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Constructing JButton with a array size of 4
buttons = new JButton[4];
//Setting up the container ready for the components to be added.
Container pane = getContentPane();
setContentPane(pane);
//Setting up the container layout
GridLayout grid = new GridLayout(2,2);
pane.setLayout(grid);
//Constructing all 4 JButtons using "for loop" and add them in the container
for(int count=0; count<buttons.length; count++) {
buttons[count] = new JButton(operation[count]);
pane.add(buttons[count]);
}
//Implemeting Even-Listener on JButton button[0] which is addition
buttons[0].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try { //fetch an error using "try-catch" function.
//Initializing important variables for operation
String input1, input2;
int num1, num2, result;
//Making two JOptionPane inputs
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
//Converting the inputs to integer in order to do the Arithmetic operation by parsing the inputs.
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
//Processing Arithmetic Operation
result = num1 + num2;
//Display the result using JOptionPane
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){ //Catch the error if the user inputs a non-integer value
//Display the error
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[1] which is subtraction
buttons[1].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 - num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[2] which is multiplication
buttons[2].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 * num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[3] which is division
buttons[3].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 / num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
buttons[0].setMnemonic('A');
buttons[1].setMnemonic('S');
buttons[2].setMnemonic('M');
buttons[3].setMnemonic('D');
/**Set all the Components Visible.
* If it is set to "false", the components in the container will not be visible.
*/
setVisible(true);
setResizable(false); //Fix window height and width
}
//Main Method
public static void main (String[] args) {
arithmeticOperationJOptionPane pjtf = new arithmeticOperationJOptionPane();
}
}
Important Part of the Program:
//Constructing all 4 JButtons using "for loop" and add them in the container
for(int count=0; count<buttons.length; count++) {
buttons[count] = new JButton(operation[count]);
pane.add(buttons[count]);
}
//Implemeting Even-Listener on JButton button[0] which is addition
buttons[0].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try { //fetch an error using "try-catch" function.
//Initializing important variables for operation
String input1, input2;
int num1, num2, result;
//Making two JOptionPane inputs
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
//Converting the inputs to integer in order to do the Arithmetic operation by parsing the inputs.
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
//Processing Arithmetic Operation
result = num1 + num2;
//Display the result using JOptionPane
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){ //Catch the error if the user inputs a non-integer value
//Display the error
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[1] which is subtraction
buttons[1].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 - num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[2] which is multiplication
buttons[2].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 * num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
//Implemeting Even-Listener on JButton button[3] which is division
buttons[3].addActionListener(
new ActionListener() {
//Handle JButton event if it is clicked
public void actionPerformed(ActionEvent event) {
try {
String input1, input2;
int num1, num2, result;
input1 = JOptionPane.showInputDialog("Please Input First Number: ");
input2 = JOptionPane.showInputDialog("Please Input Second Number: ");
num1 = Integer.parseInt(input1);
num2 = Integer.parseInt(input2);
result = num1 / num2;
JOptionPane.showMessageDialog(null,result,"Result:",JOptionPane.INFORMATION_MESSAGE);
} catch (NumberFormatException e){
JOptionPane.showMessageDialog(null, "Please Input a Integer","Error",JOptionPane.ERROR_MESSAGE);
}
}
}
);
