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Java Button Placement using BorderLayout

This code displays nothing, I have exhausted many avenues but it does not display anything on the GUI (I have a main class that calls this as well already). Please help. I am trying to put the two JButtons horizontally at the bottom of the page and the JTextField and JLabel at the center of the screen.
package test;
import javax.swing.*;
import java.awt.*;
public class Gui extends JFrame {
private JLabel label;
private JButton clear;
private JButton copy;
private JTextField textfield;
public Gui(){
super("test");
clear = new JButton("Clear");
copy = new JButton("Copy");
label = new JLabel("");
textfield = new JTextField("enter text here");
JPanel bottom = new JPanel(new BorderLayout());
JPanel subBottom = new JPanel();
subBottom.add(copy);
subBottom.add(clear);
JPanel centre = new JPanel (new BorderLayout());
JPanel subCentre = new JPanel();
subCentre.add(label);
subCentre.add(textfield);
bottom.add(subBottom, BorderLayout.PAGE_END);
centre.add(subCentre, BorderLayout.CENTER);
}
}

Your code is a bit over-complicated. You only need two panels, centre, and buttons. There are two reasons your UI is not showing up:
You never added the panels to the frame
You never set visible to true(Achieve this by using setVisible(true)), unless you did this in the class you ran it in.
One simple way to achieve your desired UI is like so(I added a main method to show the window):
import javax.swing.*;
import java.awt.*;
public class test extends JFrame {
public Test() {
super("test");
JPanel buttons = new JPanel();
JPanel centre = new JPanel();
add(buttons, BorderLayout.SOUTH); //these lines add the
add(centre, BorderLayout.CENTER); //panels to the frame
JButton clear = new JButton("Clear"); // No need
JButton copy = new JButton("Copy"); // to declare
JLabel label = new JLabel("Label"); // these
JTextField textfield = new JTextField("enter text here"); // privately
buttons.add(copy);
buttons.add(clear);
centre.add(label);
centre.add(textfield);
pack();
setLocationRelativeTo(null);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
} //end constructor
//added main method to run the UI
public static void main(String[] args) {
new Experiments();
} //end main
} //end class
And it shows the window:

I got closer but its not pretty code, the JFrame is 500x500 so this works based on that... any better suggestions than what I have?
package lab6;
import javax.swing.*;
import java.awt.*;
public class Gui extends JFrame {
private JLabel label;
private JButton clear;
private JButton copy;
private JTextField textfield;
public Gui(){
super("test");
clear = new JButton("Clear");
copy = new JButton("Copy");
label = new JLabel("label");
textfield = new JTextField("enter text here");
JPanel masterPanel = new JPanel(new BorderLayout());
JPanel top = new JPanel();
top.setPreferredSize(new Dimension(100, 200));
JPanel bottom = new JPanel();
JPanel subBottom = new JPanel();
subBottom.add(copy);
subBottom.add(clear);
JPanel centre = new JPanel ();
JPanel subCentre = new JPanel();
subCentre.add(label);
subCentre.add(textfield);
bottom.add(subBottom);
centre.add(subCentre);
masterPanel.add(bottom, BorderLayout.PAGE_END);
masterPanel.add(top, BorderLayout.PAGE_START);
masterPanel.add(centre, BorderLayout.CENTER);
add(masterPanel);
}
}

Why is my text field not appearing?

I have to create a text field, a text area, and two buttons, but I am stuck on the text field because I cant get it to appear when I run my program. My JFrame keeps appearing empty.
public class SentanceBuilder extends JFrame {
private JTextField textField = new JTextField(50);
private JTextArea textArea = new JTextArea(200,200);
private JButton Submit = new JButton();
private JButton Cancel = new JButton();
public SentanceBuilder(){
textField.setVisible(true);
textField.setLocation(50, 50);
this.textField();
this.setSize(400, 300);
this.setLocationRelativeTo(null);
this.setVisible(true);
}
public void textField(){
String textContent = textField.getText();
}
}

You never add the textField variable to a container such as a JPanel that is held by the top-level window, such as a JFrame. In fact, in your code, you add nothing to your JFrame!
If this were my GUI, I'd
Create my JTextField
Create a main JPanel to hold my components.
Add it and other components to the main JPanel via the JPanel's add(...) method.
Add the main JPanel to the JFrame's contentPane via the JFrame's add(...) method.
Call pack() and then setVisible(true) on the JFrame, but only after adding all components to it, not before.
Read the Swing tutorials since this beats guessing every time. You can get links to the tutorials at the Swing Tag Info link.
e.g.,
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class MyFoo extends JFrame {
private static final long serialVersionUID = 1L;
private JTextField textField = new JTextField(10);
private JButton button = new JButton("Foo Button");
public MyFoo() {
super("My JFrame");
// so Java will end when GUI is closed
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// code to be called when button is pushed
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO code that runs when button is pushed.
}
});
// panel to hold everything
JPanel mainPanel = new JPanel();
// add all to the panel
mainPanel.add(new JLabel("Text Field:"));
mainPanel.add(textField);
mainPanel.add(button);
// add the panel to the main GUI
add(mainPanel);
}
// start up code
private static void createAndShowGui() {
JFrame mainFrame = new MyFoo();
mainFrame.pack();
mainFrame.setLocationRelativeTo(null);
mainFrame.setVisible(true);
}
public static void main(String[] args) {
// call start up code in a Swing thread-safe way
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

JButtons not appearing on my JFrame

I am making a program that includes a GUI. For some reason, the JButton objects that I have created are not showing up onto my JFrame when I run the program. Here is the code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ReverseAStringMain extends JPanel {
private JButton enterButton, exitButton;
private JTextField textField;
private JPanel buttonPanel;
private JTextArea textArea;
public ReverseAStringMain(){
JButton enterButton = new JButton("Enter");
JButton exitButton = new JButton("Exit");
enterButton.setPreferredSize(new Dimension(60,60));
exitButton.setPreferredSize(new Dimension(60,60));
ButtonListener listener = new ButtonListener();
enterButton.addActionListener(listener);
exitButton.addActionListener(listener);
buttonPanel = new JPanel();
buttonPanel.setPreferredSize(new Dimension(200,50));
buttonPanel.setBackground(Color.black);
buttonPanel.add(enterButton);
buttonPanel.add(exitButton);
textField = new JTextField();
textField.setSize(200, 100);
textArea = new JTextArea();
textArea.add(textField);
add(buttonPanel);
add(textField);
}
//Creating a ButtonListener class that implements the ActionListener interface
private class ButtonListener implements ActionListener{
#Override
//Overriding the ActionPerformed method of ActionListener
public void actionPerformed(ActionEvent action) {
if(action.getSource()== enterButton)
enterButton();
if(action.getSource()== exitButton)
System.exit(0);
}
}
private void enterButton() {
// TODO Auto-generated method stub
}
public static void main (String[] args){
JFrame frame = new JFrame("Raj's Reverse a String Program");
frame.setBackground(Color.white);
frame.setVisible(true);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setSize(new Dimension(600,600));
//frame.pack();
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new ReverseAStringMain());
}
}
If there are any problems or improvements I can make in my code, please let me know!

You're adding the components to your JFrame after it's visible. You should either add them to the JFrame before it's visible, or revalidate the JFrame after you add the components.

When I load your code (after making it a lot shorter in height), this is what I see:
I suspect this is more along the lines of what you expect to see.
Here is how I did it. Look carefully at:
The numbers provided to the BorderLayout constructor for white space between the panels.
The EmptyBorder for white space around the controls.
The use of pack() to shrink the GUI to the natural size.
The use of size hints in the construction of the text field and text area.
The use of a second layout - commonly known as a combined, or nested, layout.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class ReverseAStringMain extends JPanel {
private JButton enterButton, exitButton;
private JTextField textField;
private JPanel pageTopPanel;
private JTextArea textArea;
public ReverseAStringMain(){
super(new BorderLayout(10,10));
setBorder(new EmptyBorder(5,15,5,15));
JButton enterButton = new JButton("Enter");
JButton exitButton = new JButton("Exit");
pageTopPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
pageTopPanel.setBackground(Color.black);
pageTopPanel.add(enterButton);
pageTopPanel.add(exitButton);
textField = new JTextField(5);
pageTopPanel.add(textField);
textArea = new JTextArea(4,40);
add(pageTopPanel, BorderLayout.PAGE_START);
add(textArea); // defaults to CENTER
}
public static void main (String[] args){
Runnable r = new Runnable() {
public void run() {
JFrame frame = new JFrame("XXX's Laid out Program");
frame.setBackground(Color.white);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new ReverseAStringMain());
frame.pack();
frame.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
General Tips
Java GUIs might have to work on a number of platforms, on different screen resolutions & using different PLAFs. As such they are not conducive to exact placement of components. To organize the components for a robust GUI, instead use layout managers, or combinations of them1, along with layout padding & borders for white space2.

Generally, you want to set the frame visible After adding components
JFrame frame = new JFrame("Raj's Reverse a String Program");
frame.setBackground(Color.white);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setSize(new Dimension(600,600));
//frame.pack();
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new ReverseAStringMain());
frame.setVisible(true); <<------
Also, it is better practice to use .pack() insteack of .setSize(), so you had it right in the commented out //.pack()
If you wanted to set a size to the panel, you would override the getPreferredSize() like this
public Dimension getPreferredSize() {
return new Dimension(300, 300); // or whatever size you want
}
When you .pack(), this preferred size will be respected by the frame.
Also, not, setting the size of the JTextField won't work. What you want to do is pass it an integer value for the number of character spaces, like this
textField = new JTextField(20);
See an edited version of your program, with all the above mentioned points. One thing I also did was get rid of all your .setPreferredSizes. You will see the difference
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ReverseAStringMain extends JPanel {
private JButton enterButton, exitButton;
private JTextField textField;
private JPanel buttonPanel;
private JTextArea textArea;
public ReverseAStringMain() {
JButton enterButton = new JButton("Enter");
JButton exitButton = new JButton("Exit");
//enterButton.setPreferredSize(new Dimension(60, 60));
//exitButton.setPreferredSize(new Dimension(60, 60));
ButtonListener listener = new ButtonListener();
enterButton.addActionListener(listener);
exitButton.addActionListener(listener);
buttonPanel = new JPanel();
//buttonPanel.setPreferredSize(new Dimension(200, 50));
buttonPanel.setBackground(Color.black);
buttonPanel.add(enterButton);
buttonPanel.add(exitButton);
textField = new JTextField(20);
//textField.setSize(200, 100); /// <<-----------
textArea = new JTextArea();
textArea.add(textField);
add(buttonPanel);
add(textField);
}
public Dimension getPreferredSize() {
return new Dimension(600, 600);
}
// Creating a ButtonListener class that implements the ActionListener
// interface
private class ButtonListener implements ActionListener {
#Override
// Overriding the ActionPerformed method of ActionListener
public void actionPerformed(ActionEvent action) {
if (action.getSource() == enterButton)
enterButton();
if (action.getSource() == exitButton)
System.exit(0);
}
}
private void enterButton() {
// TODO Auto-generated method stub
}
public static void main(String[] args) {
JFrame frame = new JFrame("Raj's Reverse a String Program");
frame.setBackground(Color.white);
frame.getContentPane().add(new ReverseAStringMain());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Have a look at the Swing tutorial trail for more information on creating GUIs with Swing.

Try to add the buttonPanel to a Container, like this. And extend JFrame instead
Container contentpane = getContentPane();
contentPane.add(buttonPanel);

Overlapping panel swing

I'm trying to do the following layout, where all JPanels are visible with the exception of panel2 when the program starts. When the user clicks btn1 then JCalendar and panel3 are set to invisible and panel2 becomes visible. The problem I'm having is that panel2 is not showing up with btn1 is clicked. However if i change the borderlayout of panel2 to one that is not being used (in this case WEST) it will show when the button is clicked, but its aligned on the left side and i want it to be centered across the form.
Code:
public class GUI extends JFrame implements ActionListener, PropertyChangeListener
{
private JPanel panel1, panel2, panel3;
private com.toedter.calendar.JCalendar calendar;
private Button btn1, btn2;
private JLabel label1, label2;
public GUI()
{
init();
}
private void init()
{
//panel1 components
panel1 = new JPanel();
btn1 = new JButton("Click me");
panel1.add(btn1);
//panel2 components
panel2 = new JPanel();
label1 = new JLabel("Time:");
label2 = new JLabel("Date:");
panel2.add(label1); panel2.add(label2);
//JCalendar
calendar = new com.toedter.calendar.JCalendar();
//panel3
panel3 = new JPanel();
//Add panels to JFrame
add(panel1, BorderLayout.NORTH);
add(calendar, BorderLayout.CENTER);
add(panel2, BorderLayout.CENTER); //if i set this to WEST it show!!
add(panel3, BorderLayout.EAST);
//event handling
btn1.addActionListener(this);
//hide panel2
panel2.setVisible(false);
pack();
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource().equals(btn1)
{
calendar.setVisible(false);
panel3.setVisible(false);
panel2.setVisible(true); //make panel2 visible
panel2.updateUI();
revalidate();
repaint();
}
}
public static void main(String args[])
{
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new GUI().setVisible(true);
}
});
}
When i click btn1, JCalendar and panel3 is invisible but panel2 does not show

There are a number of issues that I can find...
BorderLayout will only ever allow a single component to occupy any given position. That is, two components can not share the CENTER position at the same time, regardless if one is invisible or not.
You should never call updateUI, this is used to tell UI components that the look and feel has changed that they should update in response to it.
Use revalidate to tell the container that some change has occurred to the layout that it should perform a new layout process...
Before click...
After Click...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
public class GUI extends JFrame implements ActionListener, PropertyChangeListener {
private JPanel panel1, panel2, panel3;
// private com.toedter.calendar.JCalendar calendar;
private JPanel calendar;
private JButton btn1, btn2;
private JLabel label1, label2;
public GUI() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
init();
}
private void init() {
//panel1 components
panel1 = new JPanel();
btn1 = new JButton("Click me");
panel1.add(btn1);
//panel2 components
panel2 = new JPanel();
label1 = new JLabel("Time:");
label2 = new JLabel("Date:");
panel2.add(label1);
panel2.add(label2);
//JCalendar
calendar = new JPanel();//new com.toedter.calendar.JCalendar();
calendar.setBorder(new LineBorder(Color.RED));
calendar.add(new JLabel("Calendar"));
//panel3
panel3 = new JPanel();
panel3.setBorder(new LineBorder(Color.BLUE));
panel3.add(new JLabel("Panel3"));
panel2.setBorder(new LineBorder(Color.GREEN));
//Add panels to JFrame
add(panel1, BorderLayout.NORTH);
add(calendar, BorderLayout.WEST);
add(panel2, BorderLayout.CENTER);
add(panel3, BorderLayout.EAST);
//event handling
btn1.addActionListener(this);
//hide panel2
panel2.setVisible(false);
pack();
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource().equals(btn1)) {
calendar.setVisible(false);
panel3.setVisible(false);
panel2.setVisible(true); //make panel2 visible
// panel2.updateUI();
revalidate();
repaint();
}
}
public static void main(String args[]) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
new GUI().setVisible(true);
}
});
}
#Override
public void propertyChange(PropertyChangeEvent evt) {
}
}
Now, I'm pretty sure this won't meet you over all requirements (as I see them)...You have at least two options...
Remove the Calendar component and add panel2 to the CENTER position when the button is clicked
Preferably, use a CardLayout

BorderLayout doesn't do overlapping, IIRC none of the layout managers are about "overlapping layout".
You'll need to do it a different way -- try using JLayeredPane with your existing JPanel & BorderLayout as the bottom layer, and then your (optional) panel as the top layer.
See: http://docs.oracle.com/javase/tutorial/uiswing/components/layeredpane.html

Java Swing: How to change GUI dynamically

I need to add components dynamically. Moreover, I need to alter the layout dynamically.

For reference, here's an sscce that shows the essential method, validate(). This more elaborate example shows both requirements: it changes the layout and adds components dynamically.
import java.awt.*;
import java.awt.event.ActionEvent;
import javax.swing.*;
/** #see http://stackoverflow.com/questions/5750068 */
public class DynamicLayout extends JPanel {
private static final LayoutManager H = new GridLayout(1, 0);
private static final LayoutManager V = new GridLayout(0, 1);
public DynamicLayout() {
this.setLayout(H);
this.setPreferredSize(new Dimension(320, 240));
for (int i = 0; i < 3; i++) {
this.add(new JLabel("Label " + String.valueOf(i), JLabel.CENTER));
}
}
private void display() {
JFrame f = new JFrame("DynamicLayout");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
JPanel p = new JPanel();
p.add(new JButton(new AbstractAction("Horizontal") {
#Override
public void actionPerformed(ActionEvent e) {
DynamicLayout.this.setLayout(H);
DynamicLayout.this.validate();
}
}));
p.add(new JButton(new AbstractAction("Vertical") {
#Override
public void actionPerformed(ActionEvent e) {
DynamicLayout.this.setLayout(V);
DynamicLayout.this.validate();
}
}));
f.add(p, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new DynamicLayout().display();
}
});
}
}

Example of changing the layout Dynamically :
package swinglayout;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class LayoutChanger implements ActionListener{
JButton b1;
JButton b2;
JButton b3;
JButton b4;
JButton b5;
JButton b6;
/** This button set the flowlayout on panel2 with left orientation */
JButton flowLayout;
/** This button set the Gridlayout of 2,3 grid on panel2 */
JButton gridLayout;
/** This button set the Borderlayout on panel2*/
JButton borderLayout;
/**
* This panel is control panel where we use button to change
* layout of another panel
*/
JPanel panel;
/** This panel contain multiple button from b1 to b6 */
JPanel panel2;
JFrame frame;
public LayoutChanger() {
//set Default Look and Feel on frame
JFrame.setDefaultLookAndFeelDecorated(true);
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container con = frame.getContentPane();
con.setLayout(new BorderLayout());
panel = new JPanel();
panel2 = new JPanel();
//This button are used to only showing the layout effect
b1 = new JButton("HelloButton1");
b2 = new JButton("HelloButton2");
b3 = new JButton("HelloButton3");
b4 = new JButton("HelloButton4");
b5 = new JButton("HelloButton5");
b6 = new JButton("HelloButton6");
// By default panel have layout
panel2.add(b1);
panel2.add(b2);
panel2.add(b3);
panel2.add(b4);
panel2.add(b5);
panel2.add(b6);
// Layout changer button
flowLayout = new JButton("FlowLayout");
gridLayout = new JButton("GridLayout");
borderLayout = new JButton("BorderLayout");
//call Action listener on every layout changer button
flowLayout.addActionListener(this);
gridLayout.addActionListener(this);
borderLayout.addActionListener(this);
panel.add(flowLayout);
panel.add(gridLayout);
panel.add(borderLayout);
// add layout changer button panel at a top
//button panel at the center of container
con.add(panel, BorderLayout.PAGE_START);
con.add(panel2, BorderLayout.CENTER);
frame.setVisible(true);
frame.pack();
}
public void actionPerformed(ActionEvent e) {
//set the flowlayout on panel2
if(e.getSource() == flowLayout) {
FlowLayout flow = new FlowLayout(FlowLayout.LEFT);
panel2.setLayout(flow);
panel2.validate();
}
//set the gridlayout on panel2
if(e.getSource() == gridLayout) {
GridLayout grid = new GridLayout(2,3);
panel2.setLayout(grid);
panel2.validate();
}
//set the gridlayout but the problem if we don't set the constraint
//all button are set on center. So you remove the all button from panel
//Then set grid layout on panel and add them with constraints.
if(e.getSource() == borderLayout) {
panel2.remove(b1);
panel2.remove(b2);
panel2.remove(b3);
panel2.remove(b4);
panel2.remove(b5);
panel2.remove(b6);
BorderLayout border = new BorderLayout();
panel2.setLayout(border);
panel2.add(b1,BorderLayout.NORTH);
panel2.add(b2,BorderLayout.SOUTH);
panel2.add(b3,BorderLayout.EAST);
panel2.add(b4,BorderLayout.WEST);
panel2.add(b5,BorderLayout.CENTER);
panel2.add(b6,BorderLayout.BEFORE_FIRST_LINE);
panel2.validate();
}
}
public static void main(String args[]) {
new LayoutChanger();
}
}
One thing remember is you set new layout on panel don't forgot call the method validate() on panel.If you don't call this method you don't see the effect of change in layout. If you want to see the effect with out call the method you must resize the frame.
Also you can set same layout very easily like FlowLayout,GridLayout and BoxLayout, but when set BorderLayout it required constraints for adding element, so we first remove all component from panel by remove(Component comp) method then add the component in panel by constraint