I am trying to change the Image on the panel when the any of the JButtons are pressed. I have set up an array of images and need it to change to the next image in the array once it has been pressed. Here is my code:
public class SimpleGui implements ActionListener {
JButton button = new JButton("Very Happy");
JButton buttonTwo = new JButton("Happy");
JButton buttonThree = new JButton("Neutral");
JButton buttonFour = new JButton("Sad");
JButton buttonFive = new JButton("Very Sad");
static int[] ButtonArray = new int[5];
private static String[] imageList = { "res/snow.jpg", "res/test-gm.jpg" };
public int i = 0;
public static void main(String[] args) throws FileNotFoundException {
SimpleGui gui = new SimpleGui();
gui.go();
File file = new File("out.txt");
FileOutputStream fos = new FileOutputStream(file);
PrintStream ps = new PrintStream(fos);
System.setOut(ps);
ButtonArray[0] = 0;
ButtonArray[1] = 0;
ButtonArray[2] = 0;
ButtonArray[3] = 0;
ButtonArray[4] = 0;
}
public void go() {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setBackground(Color.darkGray);
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
button.addActionListener(this);
buttonTwo.addActionListener(this);
buttonThree.addActionListener(this);
buttonFour.addActionListener(this);
buttonFive.addActionListener(this);
panel.add(button);
panel.add(buttonTwo);
panel.add(buttonThree);
panel.add(buttonFour);
panel.add(buttonFive);
frame.getContentPane().add(BorderLayout.EAST, panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(650, 600);
frame.setVisible(true);
ImageIcon image = new ImageIcon(imageList[i]);
ImageIcon image1 = new ImageIcon(imageList[i + 1]);
JLabel label = new JLabel("", image, JLabel.CENTER);
JPanel panel2 = new JPanel(new BorderLayout());
panel2.add(label, BorderLayout.CENTER);
panel2.setLayout(new BoxLayout(panel2, BoxLayout.Y_AXIS));
frame.add(panel2, BorderLayout.CENTER);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent event) {
if (event.getSource() == button) {
ButtonArray[0] = 1;
ButtonArray[1] = 0;
ButtonArray[2] = 0;
ButtonArray[3] = 0;
ButtonArray[4] = 0;
System.out.println("Very Happy");
}
// buttonTwo = (JButton) event.getSource();
if (event.getSource() == buttonTwo) {
ButtonArray[0] = 0;
ButtonArray[1] = 1;
ButtonArray[2] = 0;
ButtonArray[3] = 0;
ButtonArray[4] = 0;
System.out.println("Happy");
}
// buttonThree = (JButton) event.getSource();
if (event.getSource() == buttonThree) {
ButtonArray[0] = 0;
ButtonArray[1] = 0;
ButtonArray[2] = 1;
ButtonArray[3] = 0;
ButtonArray[4] = 0;
System.out.println("Neutral");
}
// buttonFour = (JButton) event.getSource();
if (event.getSource() == buttonFour) {
ButtonArray[0] = 0;
ButtonArray[1] = 0;
ButtonArray[2] = 0;
ButtonArray[3] = 1;
ButtonArray[4] = 0;
System.out.println("Sad");
}
// buttonFive = (JButton) event.getSource();
if (event.getSource() == buttonFive) {
ButtonArray[0] = 0;
ButtonArray[1] = 0;
ButtonArray[2] = 0;
ButtonArray[3] = 0;
ButtonArray[4] = 1;
System.out.println("Very Sad");
}
// System.out.println(Arrays.toString(ButtonArray));
// ImageIcon image = (imageList[i]);
}
}
I don't really see what most parts of you code are supposed to do. So instead, here's a minimal example that should do what you are asking about: One label, and two buttons setting different images to that label.
ImageIcon[] images = new ImageIcon[] {
new ImageIcon("foo.gif"),
new ImageIcon("bar.gif"),
new ImageIcon("blub.gif")
};
JFrame frame = new JFrame("Test");
frame.getContentPane().setLayout(new FlowLayout());
JLabel label = new JLabel(images[0]);
frame.getContentPane().add(label);
JButton button1 = new JButton("Image 1");
button1.addActionListener(e -> label.setIcon(images[0]));
frame.getContentPane().add(button1);
JButton button2 = new JButton("Image 2");
button2.addActionListener(e -> label.setIcon(images[1]));
frame.getContentPane().add(button2);
frame.pack();
frame.setVisible(true);
Note that this is using Lambda functions (Java 8) but you can do the same with one or more "real" ActionListener classes. The important part is that you call label.setIcon(theImage); this part seems to be missing in your code.
If instead you want to cycle through a list or array of pictures, you can do like this:
AtomicInteger index = new AtomicInteger(0);
JButton buttonCycle = new JButton("Cycle");
buttonCycle.addActionListener(e -> label.setIcon(images[index.getAndIncrement() % images.length]));
frame.getContentPane().add(buttonCycle);
Here, the AtomicInteger is used so I can declare it as a local variable and use it in the lambda. You can just as well use a regular int if you make it a member variable of the surrounding class.
private int c = 0;
...
buttonCycle.addActionListener(e -> label.setIcon(images[c++ % images.length]));
The takeaway is: Create a counter variable, increment it each time the button is called and set the label's icon to the element with that count, module the size of the array.
I have this program that reads questions with multiple choice answers from a text file and then displays a random set of them in a JOptionPane (very question in a new Pane). In my text file the questions and the 4 options of answers are all in one line and then I divide them into new lines. Now I want to try to add JRadioButtons before every single answer. Is there someone who can help me. Thank you very much in advance. Here is my code:
Random random = new Random();
for (int i = 0; i < newRanQues; i++) {
int randIndex = random.nextInt(32) + 0;
String randomQuestion = questions.get(randIndex);
randomQuestions.add(randomQuestion);
String different = randomQuestion.replaceAll(";", "\n");
{
JOptionPane.showMessageDialog(null, different, "Question", JOptionPane.INFORMATION_MESSAGE);
JRadioButton answerA = new JRadioButton("A) " + answer[0]);
JRadioButton answerB = new JRadioButton("B) " + answer[1]);
JRadioButton answerC = new JRadioButton("C) " + answer[2]);
JRadioButton answerD = new JRadioButton("D) " + answer[3]);
ButtonGroup group = new ButtonGroup();
group.add(optionA);
group.add(optionB);
group.add(optionC);
group.add(optionD);
return;
}
This should do it:
import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class RadioButtonExample {
public static void main(String[] args) {
init();
}
private static void init() {
// create the jframe
JFrame jframe = new JFrame("Question");
// create the answers
String[] answer = { "red", "green", "yellow", "blue, no, red, no... arrrrrg" };
// create the radio buttons
JRadioButton answerA = new JRadioButton("A) " + answer[0]);
JRadioButton answerB = new JRadioButton("B) " + answer[1]);
JRadioButton answerC = new JRadioButton("C) " + answer[2]);
JRadioButton answerD = new JRadioButton("D) " + answer[3]);
// create the button group
ButtonGroup group = new ButtonGroup();
group.add(answerA);
group.add(answerB);
group.add(answerC);
group.add(answerD);
// add the question to the jframe
jframe.add(new JLabel("What is your favorite colour?"), BorderLayout.NORTH);
// create gridbag layout and constraints
GridBagLayout gbl = new GridBagLayout();
// create the panel using the gbl
JPanel pan = new JPanel(gbl);
// create the constraints
GridBagConstraints cons = new GridBagConstraints();
cons.gridwidth = 1;
cons.fill = GridBagConstraints.HORIZONTAL;
// answer 1
cons.gridx = 0;
cons.gridy = 1;
pan.add(answerA, cons);
// answer 1
cons.gridx = 0;
cons.gridy = 2;
pan.add(answerB, cons);
// answer 1
cons.gridx = 0;
cons.gridy = 3;
pan.add(answerC, cons);
// answer 1
cons.gridx = 0;
cons.gridy = 4;
pan.add(answerD, cons);
// add the panel to the jframe
jframe.add(pan, BorderLayout.CENTER);
// show the jframe
jframe.setSize(400, 400);
jframe.setVisible(true);
}
}
I have a problem.I created a program that will add two random numbers. I'm trying to put a Math.random() in a JTextField but it won't appear. Here's my code by the way:
public class RandomMathGame extends JFrame {
public RandomMathGame(){
super("Random Math Game");
int random2;
JButton lvl1 = new JButton("LEVEL 1");
JButton lvl2 = new JButton("LEVEL 2");
JButton lvl3 = new JButton("LEVEL 3");
JLabel line1 = new JLabel("Line 1: ");
final JTextField jtf1 = new JTextField(10);
JLabel line2 = new JLabel("Line 2: ");
final JTextField jtf2 = new JTextField(10);
JLabel result = new JLabel("Result: ");
final JTextField jtf3 = new JTextField(10);
JButton ans = new JButton("Answer");
JLabel score = new JLabel("Score: ");
JTextField jtf4 = new JTextField(3);
JLabel itm = new JLabel("Number of Items: ");
JTextField items = new JTextField(3);
FlowLayout flo = new FlowLayout();
setLayout(flo);
add(lvl1);
add(lvl2);
add(lvl3);
add(line1);
add(jtf1);
add(line2);
add(jtf2);
add(result);
add(jtf3);
add(ans);
add(score);
add(jtf4);
add(itm);
add(items);
setSize(140,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
lvl1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int i, j = 10;
int i1 = Integer.valueOf(jtf1.getText());
int i2 = Integer.valueOf(jtf2.getText());
int i3 = i1 + i2;
final int random1 = (int)(Math.random() * 10 + 1);
for (i = 0; i <= j + 1; i++){
try{
jtf1.setText(String.valueOf(random1));
jtf2.setText(String.valueOf(random1));
jtf3.setText(String.valueOf(i3));
}catch(Exception ex){
ex.printStackTrace();
}
}
}
});
}
Never mind the lvl2 and lvl3 because it's the same in lvl1. And also, I want to loop them 10 times. I'm having difficulties on putting up those codes. Can someone help me? Thanks for your help. :)
Updating text fields in a loop won't produce the animated display that you likely want; only the last update will be seen. Instead, use a javax.swing.Timer to periodically update the fields. Related examples may be found here, here and here.
public class NewAccountApplet extends JApplet implements ActionListener{
JPanel jp1, jp2, jp3, jp4, jp5, jp6;
GridLayout productLO = new GridLayout(10,4,10,10);
int qty = 5;
JComboBox<Object>[] selectQty;
if (e.getActionCommand().equals("Login")) {
if (id.equals(checkID) && pw.equals(checkPW)) {
JOptionPane.showMessageDialog(null, "Authenticated");
JPanel content = (JPanel)getContentPane();
GridBagConstraints firstCol = new GridBagConstraints();
firstCol.weightx = 1.0;
firstCol.anchor = GridBagConstraints.WEST;
firstCol.insets = new Insets(5, 20, 5, 5);
GridBagConstraints lastCol = new GridBagConstraints();
lastCol.gridwidth = GridBagConstraints.REMAINDER;
lastCol.weightx = 1.0;
lastCol.fill = GridBagConstraints.HORIZONTAL;
lastCol.insets = new Insets(5, 5, 5, 20);
selectQty = new JComboBox[qty];
jp1.setVisible(false);
jp2.setVisible(false);
jp3.setVisible(false);
jp4.setVisible(true);
jp5.setVisible(true);
jp6.setVisible(true);
String[] itemText = {"1", "2", "3", "4", "5"};
JLabel[] items = new JLabel[6];
JLabel purchasePage = new JLabel("Items for Purchase");
jp4.add(purchasePage);
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
content.add(jp4);
jp4 = new JPanel();
jp5 = new JPanel(new GridBagLayout()); //set jp5 as a new jpanel with gridbaglayout
jp6 = new JPanel();
for(int i=0; (i<items.length); i++) {
items[i] = new JLabel(); //adds items[i] as JLabel
items[i].setText(itemText[i]); //sets text of items as itemText[]
jp5.add(items[i], firstCol); //adds items to firstcol of jp5
selectQty[i] = new JComboBox<Object>(); //JComboBox selectqty[i]
selectQty[i].setPreferredSize(new Dimension(300, 20)); //sets the size
jp5.add(selectQty[i], lastCol); //sadsdasd
}
}
else JOptionPane.showMessageDialog(null, "Wrong account information");}
I have some questions regarding adding a JComboBox into a loop to display on my JApplet.
the for loop on the bottom adds my JComboBox (selectQty) to the screen. But I get an error message on eclipse where i coded as: items[i].setText(itemText[i]);.
It shows up my JPanel jp4 correctly. but the JPanel jp5 is not showing up.. I wonder what is wrong...
So to summarize, the code compiles (with other codes that are not on here), but japplet only shows jp4 jpanel, and error occrs on line: items[i].setText(itemText[i]);.
itemText has 5 elements {"1", "2", "3", "4", "5"} but JLabel[] items = new JLabel[6] items has 6.
You appear to be re-creating jp5 but neither removing the old instance or adding the new instance...
// This suggests that jp5 has already been created
jp5.setVisible(true);
//...
// But you create a new instance here
jp5 = new JPanel(new GridBagLayout());
// Then add stuff to it...
Try using jp5.removeAll() instead of jp5 = new JPanel(new GridBagLayout());
The likely cause of your error is probably IndexOutOfBoundsException caused by the fact the itemText and items have different numbers of elements
String[] itemText = {"1", "2", "3", "4", "5"};
JLabel[] items = new JLabel[6];
//...
for(int i=0; (i<items.length); i++) {
items[i] = new JLabel(); //adds items[i] as JLabel
// Error here on the last element...
items[i].setText(itemText[i]); //sets text of items as itemText[]
Instead, consider using something like...
String[] itemText = {"1", "2", "3", "4", "5"};
JLabel[] items = new JLabel[itemText.length];
And remember, magic numbers are a bad idea
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.logging.*;
public class NewAccountApplet extends JApplet implements ActionListener{
/**
*
*/
private static final long serialVersionUID = 1L;
JLabel titlePage;
JLabel[] txt;
JTextField[] jtf;
JButton accept, decline;
JPanel jp1, jp2, jp3, jp4, jp5, jp6;
String[] accountlist = {"Select Account Type.", "Customer", "Admin"};
JComboBox<Object> textAlignment = new JComboBox<Object>(accountlist);
GridLayout productLO = new GridLayout(10,4,10,10);
int qty = 5;
JComboBox<Object>[] selectQty;
public void init(){
setSize(400,400);
JPanel content = (JPanel)getContentPane();
GridBagConstraints firstCol = new GridBagConstraints();
firstCol.weightx = 1.0;
firstCol.anchor = GridBagConstraints.WEST;
firstCol.insets = new Insets(5, 20, 5, 5);
GridBagConstraints lastCol = new GridBagConstraints();
lastCol.gridwidth = GridBagConstraints.REMAINDER;
lastCol.weightx = 1.0;
lastCol.fill = GridBagConstraints.HORIZONTAL;
lastCol.insets = new Insets(5, 5, 5, 20);
String[] labeltxt = {"Name","Account ID","Password","E-Mail","Phone","Address","","","Account Type"};
titlePage = new JLabel("Create New Account");
txt = new JLabel[9];
jtf = new JTextField[9];
accept = new JButton("Create");
decline = new JButton("Decline");
jp1 = new JPanel();
jp2 = new JPanel(new GridBagLayout());
jp3 = new JPanel();
jp4 = new JPanel();
jp5 = new JPanel();
jp6 = new JPanel();
for(int i=0; (i<9); i++) {
txt[i] = new JLabel();
txt[i].setText(labeltxt[i]);
jp2.add(txt[i], firstCol);
jtf[i] = new JTextField();
jtf[i].setPreferredSize(new Dimension(300, 20));
jp2.add(jtf[i], lastCol);
}
jp1.add(titlePage);
jp3.add(accept);
jp3.add(decline);
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
content.add(jp1);
content.add(jp2);
content.add(jp3);
String id = this.jtf[1].getText();
String pw = this.jtf[2].getText();
jtf[6].setText(id);
jtf[7].setText(pw);
jtf[6].setVisible(false);
jtf[7].setVisible(false);
jtf[8].setVisible(false);
jp2.add(textAlignment, lastCol);
decline.addActionListener(this);
accept.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
String id = jtf[1].getText();
String pw = jtf[2].getText();
String checkID = jtf[6].getText();
String checkPW = jtf[7].getText();
String accountType = "";
String correctType = "Customer";
String chosenType = (String) textAlignment.getSelectedItem();
JPasswordField pField = new JPasswordField(10);
JPanel pPanel = new JPanel();
pPanel.add(new JLabel("Please Enter Password: "));
pPanel.add(pField);
if (e.getActionCommand().equals("Create") && (chosenType.equals("Customer"))){
JOptionPane.showMessageDialog(null, "Thank you for Joining!");
id = jtf[1].getText();
pw = jtf[2].getText();
titlePage.setText("Welcome to Final Sales!");
accept.setText("Login");
decline.setText("Cancel");
txt[6].setText("UserName");
txt[7].setText("Password");
jtf[0].setText("");
jtf[3].setText("");
jtf[4].setText("");
jtf[5].setText("");
txt[0].setVisible(false);
txt[1].setVisible(false);
txt[2].setVisible(false);
txt[3].setVisible(false);
txt[4].setVisible(false);
txt[5].setVisible(false);
textAlignment.setVisible(false);
txt[8].setVisible(false);
jtf[0].setVisible(false);
jtf[1].setVisible(false);
jtf[2].setVisible(false);
jtf[3].setVisible(false);
jtf[4].setVisible(false);
jtf[5].setVisible(false);
jtf[6].setVisible(true);
jtf[7].setVisible(true);
}
if (e.getActionCommand().equals("Create") && (chosenType.equals("Admin"))) {
JOptionPane.showMessageDialog(null, pPanel);
JOptionPane.showMessageDialog(null, "Wrong Admin Password");
}
if (e.getActionCommand().equals("Create") && (chosenType.equals("Select Account Type."))) {
JOptionPane.showMessageDialog(null, "You have selected wrong account type.");
}
if (e.getActionCommand().equals("Decline"))
System.exit(0);
if (e.getActionCommand().equals("Login")) {
if (id.equals(checkID) && pw.equals(checkPW)) {
JOptionPane.showMessageDialog(null, "Authenticated");
JPanel content = (JPanel)getContentPane();
GridBagConstraints firstCol = new GridBagConstraints();
firstCol.weightx = 1.0;
firstCol.anchor = GridBagConstraints.WEST;
firstCol.insets = new Insets(5, 20, 5, 5);
GridBagConstraints lastCol = new GridBagConstraints();
lastCol.gridwidth = GridBagConstraints.REMAINDER;
lastCol.weightx = 1.0;
lastCol.fill = GridBagConstraints.HORIZONTAL;
lastCol.insets = new Insets(5, 5, 5, 20);
selectQty = new JComboBox[qty];
jp1.setVisible(false);
jp2.setVisible(false);
jp3.setVisible(false);
jp4.setVisible(true);
jp5.setVisible(true);
jp6.setVisible(true);
String[] itemText = {"White Snapback", "Silver Necklace", "Black T Shirt", "", "5"};
JLabel[] items = new JLabel[5];
JLabel purchasePage = new JLabel("Items for Purchase");
jp4.add(purchasePage);
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
content.add(jp4);
jp4 = new JPanel();
jp5.setLayout(new GridBagLayout());
jp6 = new JPanel();
for(int i=0; (i<items.length); i++) {
items[i] = new JLabel();
items[i].setText(itemText[i]);
jp5.add(items[i], firstCol);
selectQty[i] = new JComboBox<Object>();
selectQty[i].setPreferredSize(new Dimension(300, 20));
jp5.add(selectQty[i], lastCol);
}
}
else JOptionPane.showMessageDialog(null, "Wrong account information");}
if (e.getActionCommand().equals("Cancel")) {
System.exit(0);}
}
}
public class CustomCalculator extends Frame implements ActionListener{
Panel jp1 = new Panel();
Panel jp2 = new Panel();
Panel jp3 = new Panel();
Panel jp4 = new Panel();
Panel jp5 = new Panel();
Panel center_merge = new Panel();
Label l2 = new Label("Quantity : ");
TextField l2a = new TextField(20);
Label l3 = new Label("Invoice Value : ");
TextField l3a = new TextField(20);
Label l4 = new Label("Exchange Rate : ");
TextField l4a = new TextField(20);
Label l5 = new Label("Costing(A) : ");
TextField l5a = new TextField();
Label l6 = new Label("(A + 1%)(B) : ");
Label l6a = new Label();
Label l7 = new Label("BCD (C) : ");
Label l7a = new Label("");
Label l8 = new Label("CVD (D) : ");
Label l8a = new Label("");
Label l9 = new Label("Custom Education Cess (E) : ");
Label l9a = new Label("");
Label l10 = new Label("Custom Sec & Higher Edu.Cess (F) : ");
Label l10a = new Label("");
Label l11 = new Label("Additional Duty Imports (G) : ");
Label l11a = new Label("");
Label l12 = new Label("Total (H) : ");
Label l12a = new Label("");
Label l13 = new Label("Costing+Total (I) : ");
Label l13a = new Label("");
Label l14 = new Label("(H/Quantity) (J) : ");
Label l14a = new Label("");
Label l15 = new Label("4% SAD (G/Quantity) (K) : ");
Label l15a = new Label("");
Label l16 = new Label("Net Costing (L) : ");
Label l16a = new Label("");
Label l17 = new Label("Transportation (M) : ");
TextField l17a = new TextField(5);
Label l18 = new Label("Godown Rate (N) : ");
TextField l18a = new TextField(5);
Label l19 = new Label("Brokerage (O) : ");
TextField l19a = new TextField(5);
Label l20 = new Label("Actual Costing (P) : ");
Label l20a = new Label("");
Label l21 = new Label("Small Gatepass (Q) : ");
Label l21a = new Label("");
Label l22 = new Label("Big Gatepass (R) : ");
Label l22a = new Label("");
Button l2b = new Button("reset");
Button l3b = new Button("reset");
Button l4b = new Button("reset");
Button master_reset = new Button("reset all");
Button calc = new Button("Calculate");
public CustomCalculator()
{
super("Custom Calculator");
this.setSize(800,700);
jp1.setLayout(new FlowLayout());
//jp1.setBorder(BorderFactory.createLineBorder(Color.GRAY));
jp1.add(l2);
jp1.add(l2a);
jp1.add(l2b);
jp1.add(l3);
jp1.add(l3a);
jp1.add(l3b);
jp1.add(l4);
jp1.add(l4a);
jp1.add(l4b);
jp2.setLayout(new GridLayout(6,2));
//jp2.setBorder(BorderFactory.createLineBorder(Color.GRAY));
jp2.add(l5);
jp2.add(l5a);
jp2.add(l6);
jp2.add(l6a);
jp2.add(l7);
jp2.add(l7a);
jp2.add(l8);
jp2.add(l8a);
jp2.add(l9);
jp2.add(l9a);
jp2.add(l10);
jp2.add(l10a);
jp3.setLayout(new GridLayout(6,2));
//jp3.setBorder(BorderFactory.createLineBorder(Color.GRAY));
jp3.add(l11);
jp3.add(l11a);
jp3.add(l12);
jp3.add(l12a);
jp3.add(l13);
jp3.add(l13a);
jp3.add(l14);
jp3.add(l14a);
jp3.add(l15);
jp3.add(l15a);
jp3.add(l16);
jp3.add(l16a);
jp4.setLayout(new GridLayout(6,2));
//jp4.setBorder(BorderFactory.createLineBorder(Color.GRAY));
jp4.add(l17);
jp4.add(l17a);
jp4.add(l18);
jp4.add(l18a);
jp4.add(l19);
jp4.add(l19a);
jp4.add(l20);
jp4.add(l20a);
jp4.add(l21);
jp4.add(l21a);
jp4.add(l22);
jp4.add(l22a);
center_merge.setLayout(new GridLayout(1,3));
//center_merge.setBorder(BorderFactory.createLineBorder(Color.GRAY));
center_merge.add(jp2);
center_merge.add(jp3);
center_merge.add(jp4);
jp5.setLayout(new FlowLayout());
//jp5.setBorder(BorderFactory.createLineBorder(Color.GRAY));
jp5.add(calc);
jp5.add(master_reset);
this.setLayout(new BorderLayout());
this.add(jp1,BorderLayout.NORTH);
this.add(center_merge,BorderLayout.CENTER);
this.add(jp5,BorderLayout.SOUTH);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
});
l2b.addActionListener(this);
l3b.addActionListener(this);
l4b.addActionListener(this);
calc.addActionListener(this);
master_reset.addActionListener(this);
this.setVisible(true);
}
public static void main(String[] args) {
new CustomCalculator();
}
#Override
public void actionPerformed(ActionEvent ae) {
double quantity = 0;
double invoice_value = 0;
double exchange_rate = 0;
double A=0;
double B=0;
double C=0;
double D=0;
double E=0;
double F=0;
double G=0;
double H=0;
double I=0;
double J=0;
double K=0;
double L=0;
double M = 0;
double N = 0;
double O=0;
double P=0;
double Q=0;
double R=0;
try
{
quantity = Double.parseDouble(l2a.getText());
invoice_value = Double.parseDouble(l3a.getText());
exchange_rate = Double.parseDouble(l4a.getText());
M = Double.parseDouble(l17a.getText());
N = Double.parseDouble(l18a.getText());
O = Double.parseDouble(l19a.getText());
A = invoice_value*exchange_rate;
B = A+(0.01*A);
C = 0.075*B;
D = 0.12*(B+C);
E = 0.02*(C+D);
F = 0.01*(C+D);
G = 0.04*(B+C+D+E+F);
H = C+D+E+F+G;
I = A+H;
J = H/quantity;
K = G/quantity;
L = J-K;
P = L+M+N+O;
Q = (0.12*B)/quantity;
R = Q+K;
if(ae.getActionCommand().equals("calc"))
{
l5a.setText(String.valueOf(A));
l6a.setText(String.valueOf(B));
l7a.setText(String.valueOf(C));
l8a.setText(String.valueOf(D));
l9a.setText(String.valueOf(E));
l10a.setText(String.valueOf(F));
l11a.setText(String.valueOf(G));
l12a.setText(String.valueOf(H));
l13a.setText(String.valueOf(I));
l14a.setText(String.valueOf(J));
l15a.setText(String.valueOf(K));
l16a.setText(String.valueOf(L));
l20a.setText(String.valueOf(P));
l21a.setText(String.valueOf(Q));
l22a.setText(String.valueOf(R));
}
else if(ae.getActionCommand().equals("master_reset"))
{
l5a.setText("");
l2a.setText("");
l3a.setText("");
l4a.setText("");
}
}
catch (Exception ex)
{
l5a.setText(ex.toString());
// l3a.setText(ex.toString());
}
}
}
After I click the Calculate button (button calc) the calculated values do not appear in the respective labels and an exception is shown saying java.lang.NumberFormatException: Empty string. I am not able to figure out the solution. please help.
the line exchange_rate = Double.parseDouble(l4a.getText()); gives you this exception, because there is no value in l4a and you are trying to parse it into a double value,
try printing the exception in the catch clause.
It's probably a relatively safe bet to say that it is happening here at the beginning of your function, though you should provide the actual exception and line number for us.
quantity = Double.parseDouble(l2a.getText());
invoice_value = Double.parseDouble(l3a.getText());
exchange_rate = Double.parseDouble(l4a.getText());
M = Double.parseDouble(l17a.getText());
N = Double.parseDouble(l18a.getText());
O = Double.parseDouble(l19a.getText());
Make sure that each of these fields actually has numeric text in it. I would recommend putting a logging line or an alert line to state their values before this is executed. Better yet, you can catch the first line in a debugger and look at the the values of all of the items you're calling getText() on. I bet one has an empty string.