Develop Reference

Java AWT/Swing Updating JPanel Continously Not Working

I am trying to make a program that populates a JPanel with GridLayout with the contents of a HashMap that contains String keys to JButton values. Because the size of the HashMap may change, I can't just use setText() for each button. So far I've called .removeAll() to remove the JPanel of all buttons, then I loop through the HashMap to repopulate the JPanel. I then call revalidate() on the JPanel and repaint() on the JFrame.
Current Code:
public class GUI implements Runnable, ActionListener
{
private ToDo td;
JFrame frame;
Thread t=null;
int fontsize = 18;
private Container contentPane;
private JPanel topPane;
private JButton main;
private JButton add;
private JButton settings;
private JPanel centerPane;
private JScrollPane centerScroll;
private JPanel scrollable;
private HashMap<String, JButton> items;
public static void main(String[] args) {
new GUI();
}
public GUI(){
td = new ToDo();
frame = new JFrame();
t = new Thread(this);
t.start();
frame.setMinimumSize(new Dimension(480, 640));
frame.setLayout(null);
frame.setVisible(true);
contentPane = frame.getContentPane();
contentPane.setLayout(new BorderLayout());
topPane = new JPanel();
topPane.setLayout(new GridLayout(1, 3));
topPane.setPreferredSize(new Dimension(480, 40));
main = new JButton("View Tasks");
main.setFont(new Font("Sans Serif", Font.PLAIN, fontsize));
add = new JButton("Add Task");
add.setFont(new Font("Sans Serif", Font.PLAIN, fontsize));
settings = new JButton("Settings");
settings.setFont(new Font("Sans Serif", Font.PLAIN, fontsize));
topPane.add(main);
topPane.add(add);
topPane.add(settings);
contentPane.add(topPane, BorderLayout.NORTH);
centerPane = new JPanel();
centerPane.setPreferredSize(new Dimension(480, 600));
items = new HashMap<>();
HashMap<String, Assignment> assignments = td.getAssignments();
scrollable = new JPanel();
scrollable.setLayout(new GridLayout(assignments.size(), 1));
centerScroll = new JScrollPane(scrollable);
for(String key: assignments.keySet()){
Assignment a = assignments.get(key);
JButton button = new JButton(a.getTitle() + " ｜ " + a.getDetails() + " ｜ " + a.getClassification().getCls() + " ｜ " + a.getStatus().getStatus());
button.addActionListener(this);
items.put(key, button);
scrollable.add(button);
}
centerPane.add(centerScroll);
contentPane.add(centerPane, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
public void update(int i){
HashMap<String, Assignment> assignments = td.getAssignments();
scrollable.removeAll();
scrollable.setLayout(new GridLayout(assignments.size(), 1));
for(String key: assignments.keySet()){
Assignment a = assignments.get(key);
JButton button = new JButton(Integer.toString(i));
button.addActionListener(this);
items.put(key, button);
scrollable.add(button);
}
scrollable.revalidate();
frame.repaint();
}
#Override
public void run(){
int counter = 0;
try {
while (true) {
update(counter);
t.sleep( 1000 ); // interval given in milliseconds
counter++;
}
}
catch (Exception e) {
System.out.println();
}
}
#Override
public void actionPerformed(ActionEvent e){
for(String s: items.keySet()){
if(items.get(s) == e.getSource()){
EventMenu em = new EventMenu(td, s);
}
}
}
}
The problem is that the buttons are not updating. I expect that the JPanel should be constantly repopulating with updated JButtons with different text, but it seems that the program hangs and doesn't update.
I tried making a simpler example which I modified from here, with different results:
public class DigitalWatch implements Runnable{
JFrame f;
JPanel p;
Thread t=null;
int hours=0, minutes=0, seconds=0;
String timeString = "";
JButton b;
DigitalWatch(){
f=new JFrame();
p = new JPanel();
t = new Thread(this);
t.start();
b=new JButton();
b.setBounds(100,100,100,50);
p.add(b);
f.add(p);
f.setSize(300,400);
f.setLayout(null);
f.setVisible(true);
}
public void run() {
try {
while (true) {
Calendar cal = Calendar.getInstance();
hours = cal.get( Calendar.HOUR_OF_DAY );
if ( hours > 12 ) hours -= 12;
minutes = cal.get( Calendar.MINUTE );
seconds = cal.get( Calendar.SECOND );
SimpleDateFormat formatter = new SimpleDateFormat("hh:mm:ss");
Date date = cal.getTime();
timeString = formatter.format( date );
p.removeAll();
b=new JButton(timeString);
b.setBounds(100,100,100,50);
p.add(b);
f.add(p);
p.revalidate();
f.repaint();
//printTime();
t.sleep( 1000 ); // interval given in milliseconds
}
}
catch (Exception e) {
System.out.println(e);
}
}
public static void main(String[] args) {
new DigitalWatch();
}
}
This snippet fails to draw anything, unlike the first which at least draws the objects created in the constructor.
How can I make a list or grid JPanel update procedurally and in real time and populate buttons? I know I could change the text of each button every time, but the number of buttons may change at any time.
Full code here.

you are violating Swing's single thread rule - you are not supposed to do any UI related stuff outside Swing's event dispatch thread.
Read up on it here and here.
Below is a working example. Not sure why they chose to use a button to show the time though. :-)
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.Timer;
public class DigitalWatch extends JFrame {
private DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.MEDIUM);
public DigitalWatch() {
JButton btn = new JButton(getCurrentTime());
this.getContentPane().setLayout(new FlowLayout());
this.getContentPane().add(btn);
this.setPreferredSize(new Dimension(200, 150));
this.pack();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null); // center it on the screen
new Timer(500, e -> btn.setText(getCurrentTime())).start();
}
private String getCurrentTime() {
return formatter.format(LocalTime.now());
}
public static void main(String[] args) {
new DigitalWatch().setVisible(true);
}
}

More than 1 object in a single JFrame

I'm hoping someone can push me in the right direction with this. I have 3 separate classes, Calculator, Calculator2, and a Calculator3. In principal they are all the same, except for a few changes to some of the buttons, so I'll just paste the code for Calculator. I was wondering how can I get them so all appear in a single JFrame next to each other in a main? I attached my most recent attempt of the main as well.
Here is Calculator:
public class Calculator implements ActionListener {
private JFrame frame;
private JTextField xfield, yfield;
private JLabel result;
private JButton subtractButton;
private JButton divideButton;
private JButton addButton;
private JButton timesButton;
private JPanel xpanel;
public Calculator() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
xpanel = new JPanel();
xpanel.setLayout(new GridLayout(3,2));
xpanel.add(new JLabel("x:", SwingConstants.RIGHT));
xfield = new JTextField("0", 5);
xpanel.add(xfield);
xpanel.add(new JLabel("y:", SwingConstants.RIGHT));
yfield = new JTextField("0", 5);
xpanel.add(yfield);
xpanel.add(new JLabel("Result:"));
result = new JLabel("0");
xpanel.add(result);
frame.add(xpanel, BorderLayout.NORTH);
/***********************************************************************
***********************************************************************
**********************************************************************/
JPanel southPanel = new JPanel(); //New panel for the artimatic buttons
southPanel.setBorder(BorderFactory.createEtchedBorder());
timesButton = new JButton("Multiplication");
southPanel.add(timesButton);
timesButton.addActionListener(this);
subtractButton = new JButton("Subtract");
southPanel.add(subtractButton);
subtractButton.addActionListener(this);
divideButton = new JButton("Division");
southPanel.add(divideButton);
divideButton.addActionListener(this);
addButton = new JButton("Addition");
southPanel.add(addButton);
addButton.addActionListener(this);
frame.add(southPanel , BorderLayout.SOUTH);
Font thisFont = result.getFont(); //Get current font
result.setFont(thisFont.deriveFont(thisFont.getStyle() ^ Font.BOLD)); //Make the result bold
result.setForeground(Color.red); //Male the result answer red in color
result.setBackground(Color.yellow); //Make result background yellow
result.setOpaque(true);
frame.pack();
frame.setVisible(true);
}
/**
* clear()
* Resets the x and y field to 0 after invalid integers were input
*/
public void clear() {
xfield.setText("0");
yfield.setText("0");
}
#Override
public void actionPerformed(ActionEvent event) {
String xText = xfield.getText(); //Get the JLabel fiels and set them to strings
String yText = yfield.getText();
int xVal;
int yVal;
try {
xVal = Integer.parseInt(xText); //Set global var xVal to incoming string
yVal = Integer.parseInt(yText); //Set global var yVal to incoming string
}
catch (NumberFormatException e) { //xVal or yVal werent valid integers, print message and don't continue
result.setText("ERROR");
clear();
return ;
}
if(event.getSource().equals(timesButton)) { //Button pressed was multiply
result.setText(Integer.toString(xVal*yVal));
}
else if(event.getSource().equals(divideButton)) { //Button pressed was division
if(yVal == 0) { //Is the yVal (bottom number) 0?
result.setForeground(Color.red); //Yes it is, print message
result.setText("CAN'T DIVIDE BY ZERO!");
clear();
}
else
result.setText(Integer.toString(xVal/yVal)); //No it's not, do the math
}
else if(event.getSource().equals(subtractButton)) { //Button pressed was subtraction
result.setText(Integer.toString(xVal-yVal));
}
else if(event.getSource().equals(addButton)) { //Button pressed was addition
result.setText(Integer.toString(xVal+yVal));
}
}
}
And here is my current main:
public class DemoCalculator {
public static void main(String[] args) {
JFrame mainFrame = new JFrame("Calculators");
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Calculator calc = new Calculator();
Calculator2 calc2 = new Calculator2();
JPanel calcPanel = new JPanel(new BorderLayout());
JPanel calcPanel2 = new JPanel(new BorderLayout());
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
//calcPanel.add(calc, BorderLayout.CENTER);
//calcPanel2.add(calc2, BorderLayout.CENTER);
mainPanel.add(calcPanel);
mainPanel.add(calcPanel2);
calcPanel.add(mainPanel);
mainFrame.getContentPane().add(calcPanel);
mainFrame.getContentPane().add(calcPanel2);
mainFrame.pack();
mainFrame.setVisible(true);
}
}

You should just create a single JFrame and put your Calculator classes each into a single JPanel.Don't create a new JFrame for each class.
public class Calculator{
JPanel panel;
public Calculator(){
panel = new JPanel();
/*
* Add labels and buttons etc.
*/
panel.add(buttons);
panel.add(labels);
}
//Method to return the JPanel
public JPanel getPanel(){
return panel;
}
}
Then add the panels to your JFrame in your testers class using whatever layout best suits your needs.
public class DemoCalculator {
public static void main(String[] args) {
JPanel cal1,cal2;
JFrame frame = new JFrame("Calculators");
frame.add(cal1 = new Calculator().getPanel(),new BorderLayout().EAST);
frame.add(cal2 = new Calculator2().getPanel(),new BorderLayout().WEST);
frame.setSize(1000,600);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setResizable(false);
frame.setVisible(true);
}
}

Comparing two JTextFields with an ActionListener

what I am trying to do is compare two inputs from TextFields within a JFrame using an ActionListener. If the two inputs are equal and the user hits the button, a MessageDialog will pop up and say "equal". If they are not equal, a MessageDialog will pop up and say "not equal". I have the frame and ActionListener running, I just do not know how to take the inputs from the TextFields and compare them.
For example, if the user enters something like this,
Equal TextFields, this will pop up, Equal Message
Here is my Main Class:
public class LabFiveOne
{
public static void main(String[] args)
{
JFrame frame = new JFrame("String Equality Program");
JTextField tf1 = new JTextField(10);
tf1.setActionCommand(tf1.toString());
tfListener tfListen = new tfListener(tf1);
JTextField tf2 = new JTextField(10);
tf2.setActionCommand(tf2.toString());
JButton chEq = new JButton("Check Equality");
chEq.addActionListener(tfListen);
JPanel nPanel = new JPanel();
nPanel.add(tf1);
nPanel.add(tf2);
frame.add(nPanel, BorderLayout.NORTH);
JPanel sPanel = new JPanel();
sPanel.add(chEq);
frame.add(sPanel, BorderLayout.SOUTH);
nPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
And here is my ActionListener Class:
class tfListener implements ActionListener
{
private final JTextField tf3;
public tfListener(JTextField nameTF)
{
tf3 = nameTF;
}
#Override
public void actionPerformed(ActionEvent e)
{
if(e.getActionCommand().equals("abc"))
{
JOptionPane.showMessageDialog(null, "equal");
}
else
{
JOptionPane.showMessageDialog(null, "not equal");
}
}
}

EDIT: ok than try to change the constructor in your ActionListener Class to
public tfListener(JTextField tf1, JTextField tf2){
{
Hi :) just don't overthink and you should be fine. The simple way would be to implement the ActionListener directly to your Main Class like this:
public class LabFiveOne
{
public static void main(String[] args)
{
JFrame frame = new JFrame("String Equality Program");
final JTextField tf1 = new JTextField(10);
tf1.setActionCommand(tf1.toString());
tfListener tfListen = new tfListener(tf1);
final JTextField tf2 = new JTextField(10);
tf2.setActionCommand(tf2.toString());
JButton chEq = new JButton("Check Equality");
chEq.addActionListener(tfListen);
JPanel nPanel = new JPanel();
nPanel.add(tf1);
nPanel.add(tf2);
frame.add(nPanel, BorderLayout.NORTH);
JPanel sPanel = new JPanel();
sPanel.add(chEq);
frame.add(sPanel, BorderLayout.SOUTH);
nPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
{
class tfListener implements ActionListener
{
private final String tf1text;
private final String tf2text;
public tfListener(JTextField tf1, JTextField tf2)
{
tf1text = new String(tf1.getText());
tf1text = new String(tf2.getText());
}
#Override
public void actionPerformed(ActionEvent e)
{
if(tf1text.equal(tf2text))
{
JOptionPane.showMessageDialog(null, "equal");
}
else
{
JOptionPane.showMessageDialog(null, "not equal");
}
}
}
}

tf1.toString();
Shows you some information from the JTextField.
use another methods to get your input from the field. I mean it's the method:
tfi.getText();
Better look in a JTextField javadoc

To be honest with you, I don't think you need two classes; one for implementing the GUI and one for handling the ActionListener when you can have everything in one class like the class below
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.*;
public class LabFiveOne implements ActionListener
{
private JFrame frame;
private JPanel nPanel, sPanel;
private JTextField tf1, tf2;
private JButton chEq;
public static void main(String[] args)
{
new LabFiveOne();
}
public LabFiveOne(){
frame = new JFrame("String Equality Program");
tf1 = new JTextField(10);
tf2 = new JTextField(10);
chEq = new JButton("Check Equality");
chEq.addActionListener(this);
nPanel = new JPanel();
nPanel.add(tf1);
nPanel.add(tf2);
frame.add(nPanel, BorderLayout.NORTH);
sPanel = new JPanel();
sPanel.add(chEq);
frame.add(sPanel, BorderLayout.SOUTH);
nPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String action = e.getActionCommand();
if(action.equals("Check Equality")){
String number1 = tf1.getText();
String number2 = tf2.getText();
int num1 = Integer.valueOf(number1);
int num2 = Integer.valueOf(number2);
if(num1 == num2){
JOptionPane.showMessageDialog(null, "Equal");
}
else{
JOptionPane.showMessageDialog(null, "Not Equal");
}
}
}
}
I have everything declared globally so that the ActionPerformed method will have access the values in the Textfields.

Java grid layout GUI - how to enter new pane on event?

How can I set a button to link to a completely different grid pane? If I click the JButton "More options" for example, I want it to link me to a new page with more JButton options. Right now, everything is static.
The program right now just calculates the area of a rectangle given an length and width when you press "Calculate." The grid layout is 4 x 2, denoted by JLabel, JTextField, and JButton listed below.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class RectangleProgram extends JFrame
{
private static final int WIDTH = 400;
private static final int HEIGHT = 300;
private JLabel lengthL, widthL, areaL;
private JTextField lengthTF, widthTF, areaTF;
private JButton calculateB, exitB;
//Button handlers:
private CalculateButtonHandler cbHandler;
private ExitButtonHandler ebHandler;
public RectangleProgram()
{
lengthL = new JLabel("Enter the length: ", SwingConstants.RIGHT);
widthL = new JLabel("Enter the width: ", SwingConstants.RIGHT);
areaL = new JLabel("Area: ", SwingConstants.RIGHT);
lengthTF = new JTextField(10);
widthTF = new JTextField(10);
areaTF = new JTextField(10);
//SPecify handlers for each button and add (register) ActionListeners to each button.
calculateB = new JButton("Calculate");
cbHandler = new CalculateButtonHandler();
calculateB.addActionListener(cbHandler);
exitB = new JButton("Exit");
ebHandler = new ExitButtonHandler();
exitB.addActionListener(ebHandler);
setTitle("Sample Title: Area of a Rectangle");
Container pane = getContentPane();
pane.setLayout(new GridLayout(4, 2));
//Add things to the pane in the order you want them to appear (left to right, top to bottom)
pane.add(lengthL);
pane.add(lengthTF);
pane.add(widthL);
pane.add(widthTF);
pane.add(areaL);
pane.add(areaTF);
pane.add(calculateB);
pane.add(exitB);
setSize(WIDTH, HEIGHT);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private class CalculateButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
double width, length, area;
length = Double.parseDouble(lengthTF.getText()); //We use the getText & setText methods to manipulate the data entered into those fields.
width = Double.parseDouble(widthTF.getText());
area = length * width;
areaTF.setText("" + area);
}
}
public class ExitButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}
public static void main(String[] args)
{
RectangleProgram rectObj = new RectangleProgram();
}
}

You can use CardLayout. It allows the two or more components share the same display space.
Here is a simple example
public class RectangleProgram {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("Area of a Rectangle");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField lengthField = new JTextField(10);
JTextField widthField = new JTextField(10);
JTextField areaField = new JTextField(10);
JButton calculateButton = new JButton("Calculate");
JButton exitButton = new JButton("Exit");
final JPanel content = new JPanel(new CardLayout());
JButton optionsButton = new JButton("More Options");
optionsButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
CardLayout cardLayout = (CardLayout) content.getLayout();
cardLayout.next(content);
}
});
JPanel panel = new JPanel(new GridLayout(0, 2)) {
#Override
public Dimension getPreferredSize() {
return new Dimension(250, 100);
}
};
panel.add(new JLabel("Enter the length: ", JLabel.RIGHT));
panel.add(lengthField);
panel.add(new JLabel("Enter the width: ", JLabel.RIGHT));
panel.add(widthField);
panel.add(new JLabel("Area: ", JLabel.RIGHT));
panel.add(areaField);
panel.add(calculateButton);
panel.add(exitButton);
JPanel optionsPanel = new JPanel();
optionsPanel.add(new JLabel("Options", JLabel.CENTER));
content.add(panel, "Card1");
content.add(optionsPanel, "Card2");
frame.add(content);
frame.add(optionsButton, BorderLayout.PAGE_END);
frame.pack();
frame.setVisible(true);
}
});
}
}
Read How to Use CardLayout

How I can get output from 1st frame textfield input text to 2nd frame textArea

Here is my 1st frame - I want went I input text in textfield example name then click button report will display output to 2nd frame using textArea... please help me
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class Order extends JFrame implements ActionListener
{
private JPanel pInfo,pN, pIC, pDate,Blank,pBlank, button, pTotal;
private JLabel nameL,icL,DateL;
private JTextField nameTF, icTF;
private JFormattedTextField DateTF;
private JButton calB,clearB,exitB,reportB;
public Order()
{
Container contentPane = getContentPane();
contentPane.setLayout(new BorderLayout());
contentPane.setBackground(Color.gray);
pInfo = new JPanel();
pN = new JPanel();
pIC = new JPanel();
pDate = new JPanel();
nameTF = new JTextField(30);
icTF = new JTextField(30);
DateTF = new JFormattedTextField(
java.util.Calendar.getInstance().getTime());
DateTF.setEditable (false);
DateTF.addActionListener(this);
nameL = new JLabel(" NAME : ",SwingConstants.RIGHT);
icL = new JLabel(" IC : ",SwingConstants.RIGHT);
DateL = new JLabel(" DATE :",SwingConstants.RIGHT);
pInfo.setLayout(new GridLayout(10,2,5,5));
pInfo.setBorder(BorderFactory.createTitledBorder
(BorderFactory.createEtchedBorder(),"ORDER"));
pN.add(nameL);
pN.add(nameTF);
pIC.add(icL);
pIC.add(icTF);
pDate.add(DateL);
pDate.add(DateTF);
pInfo.add(pN);
pInfo.add(pIC);
pInfo.add(pDate);
pInfo.setBackground(Color.GRAY);
pN.setBackground(Color.gray);
pIC.setBackground(Color.gray);
pDate.setBackground(Color.gray);
nameL.setForeground(Color.black);
icL.setForeground(Color.black);
DateL.setForeground(Color.black);
nameTF.setBackground(Color.pink);
icTF.setBackground(Color.pink);
DateTF.setBackground(Color.pink);
contentPane.add(pInfo,BorderLayout.CENTER);
Blank = new JPanel();
pBlank = new JPanel();
button = new JPanel();
calB = new JButton("CALCULATE");
calB.setToolTipText("Click to calculate");
clearB = new JButton("RESET");
clearB.setToolTipText("Click to clear");
reportB = new JButton ("REPORT");
reportB.setToolTipText ("Click to print");
exitB = new JButton("EXIT");
exitB.setToolTipText("Click to exit");
Blank.setLayout(new GridLayout(2,2));
Blank.setBorder(BorderFactory.createTitledBorder
(BorderFactory.createEtchedBorder(),""));
button.setLayout(new GridLayout(1,4));
button.add(calB,BorderLayout.WEST);
button.add(clearB,BorderLayout.CENTER);
button.add(reportB,BorderLayout.CENTER);
button.add(exitB,BorderLayout.EAST);
Blank.add(pBlank);
Blank.add(button);
contentPane.add(Blank,BorderLayout.SOUTH);
Blank.setBackground(Color.gray);
pBlank.setBackground(Color.gray);
calB.setForeground(Color.black);
clearB.setForeground(Color.black);
reportB.setForeground(Color.black);
exitB.setForeground(Color.black);
calB.setBackground(Color.pink);
clearB.setBackground(Color.pink);
reportB.setBackground(Color.pink);
exitB.setBackground(Color.pink);
calB.addActionListener(this);
clearB.addActionListener(this);
reportB.addActionListener(this);
exitB.addActionListener(this);
}
public void actionPerformed(ActionEvent p)
{
if (p.getSource() == calB)
{
}
else if (p.getSource() == clearB)
{
}
else if (p.getSource () == reportB)
{
}
else if (p.getSource() == exitB)
{
}
}
public static void main (String [] args)
{
Order frame = new Order();
frame.setTitle("Order");
frame.setSize(500,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setVisible(true);
frame.setLocationRelativeTo(null);//center the frame
}
}

If you only have one String to pass, add it to the constructor of your second JFrame:
public class SecondFrame extends JFrame {
public SecondFrame(String someValueFromFirstFrame) {
someTextField.setText(someValueFromFirstFrame);
}
}
and pass it when creating the second JFrame:
SecondFrame secondFrame = new SecondFrame(firstTextField.getText());
If there is more than one attribute to pass, consider putting them together in another class and pass the instance of this class. This saves you from changing the constructor every time you need to pass an additional variable.

Simply add some reference to the first frame in the second or pass the value you're interested in to the second frame before you display it.
As for the code example you requested:
public class SecondFrame extends JFrame {
private JFrame firstFrame;
public SecondFrame(JFrame firstFrame) {
this.firstFrame = firstFrame;
}
}
Now you can obtain everything there is to obtained from the firstFrame through the internal reference to it.