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Nothing is showing up on my pop up window for JLabel

I'm trying to create a simple script that will allow a pop up of images and text. The window is poping up but its blank with nothing on it. Anyone know what I am doing wrong?
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.*;
public class Thermomter {
public static void main(String[] args) {
ImageIcon cold = new ImageIcon("cold_thermomtor.png");
JLabel label = new JLabel();
label.setIcon(cold);
label.setText("omg this is painfull");
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
frame.setVisible(true);
frame.add(label);
}
}

Try to put
frame.add(label);
first, after:
JFrame frame = new JFrame();
Like this:
JFrame frame = new JFrame();
frame.add(label);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
frame.setVisible(true);

A call to frame.pack(); before calling setVisible(true) will ensure all the elements inside get sized correctly before displaying them.
The pack method sizes the frame so that all its contents are at or above their preferred sizes
[...]
[...] pack leaves the frame layout manager in charge of the frame size, and layout managers are good at adjusting to platform dependencies and other factors that affect component size.

Two JPanels in one JFrame

I want to use two JPanels in one JFrame, with an invisible horizontal line between them. I played a little bit and got this:
public class Application {
public static void main(String[] args)
{
JFrame jframe = new JFrame();
jframe.setSize(500,700);
jframe.setVisible(true);
jframe.setTitle("Title");
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jframe.setResizable(false);
JSplitPane splitPane = new JSplitPane();
JPanel leftPanel = new JPanel();
JPanel rightPanel = new JPanel();
splitPane.setOrientation(JSplitPane.HORIZONTAL_SPLIT);
splitPane.setDividerLocation(250);
splitPane.setLeftComponent(leftPanel);
splitPane.setRightComponent(rightPanel);
jframe.add(splitPane);
}
}
Now, the first problem is how can I turn off the "resizability" of the Line between the panels? And how do I make it "invisible"? Maybe use something else than split pane?
Second of all, how do can I work with only one side of the JPanel?
(I am working on an application that lets you draw a circle on the left hand side).
This seems like an easy question but I am relatively new to Java.

As said before in a comment by #MadProgrammer you can use BorderLayout or GridBagLayout but as you're placing the "split" line right in the middle of both panels you could use GridLayout which will make both panels be of the same size no matter if the window is resized.
I didn't tried with GridBagLayout but I did an example on how you could achieve this pane separation without using a JSplitPane.
With GridLayout all you need to do is add the elements to the left pane (in my example I used a JLabel to differentiate them) while in BorderLayout you need to specify that the panel where you'll be painting the circle to be aligned to the left (WEST constant) as I did.
However if you use BorderLayout approach and add text or elements to the right pane, they will be aligned to the right, you can fix it by "boxing" the elements in another pane with a different Layout.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Application {
private JFrame frame;
private JPanel containerPane;
private JPanel topPane;
private JPanel bottomPane;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Application().createAndShowGui();
}
});
}
public void createAndShowGui() {
frame = new JFrame("Example of 2 panels");
containerPane = new JPanel();
topPane = new JPanel();
bottomPane = new JPanel();
containerPane.setLayout(new GridLayout(2, 1));
topPane.setLayout(new GridLayout(1, 2));
bottomPane.setLayout(new BorderLayout());
topPane.add(new JLabel("Left side"));
topPane.add(new JLabel("Right side"));
bottomPane.add(new JLabel("Left side"), BorderLayout.WEST);
bottomPane.add(new JLabel("Right side"), BorderLayout.EAST);
topPane.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.BLUE), "Using GridLayout"));
bottomPane.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.BLUE), "Using BorderLayout"));
containerPane.add(topPane);
containerPane.add(bottomPane);
frame.add(containerPane);
// frame.pack();
frame.setSize(500, 400);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
I didn't call pack() in this example because the size of both panels (or JLabels in this case was not tall enough to show the difference:
Using pack():
Calling setSize():
Additional tips
Don't forget to place your program on the Event Dispatch Thread (EDT), I did it by writing these lines on the main method:
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Application().createAndShowGui();
}
});
Don't place all your code on the constructor, otherwise it will be hard to maintain

It looks like you can use GridLayout to do this. Here is what i think,
public class Application {
public static void main(String[] args) {
JFrame jframe = new JFrame();
jframe.setTitle("Title");
jframe.setResizable(false);
//This creates one row and two equally divided columns
GridLayout gridLayout = new GridLayout(0, 2);
jframe.setLayout(gridLayout);
gridLayout.layoutContainer(jframe);
JPanel leftPanel = new JPanel();
leftPanel.add(new Label("Left side"));
jframe.add(leftPanel);
JPanel rightPanel = new JPanel();
rightPanel.add(new Label("Right side"));
jframe.add(rightPanel);
jframe.setSize(800, 500);
jframe.setVisible(true);
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Here is how it looks:
The panels will not resize as well as there is no line visible that seprates them.

JButton not changing size

I've researched the ways to change the size of a jbutton to be displayed on a JFrame.
I am trying both the button.setSize(200,200) and button.setPreferredSize(new Dimension(200,200)), but it does not change. Here's the code:
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JButton;
import javax.swing.JFrame;
public class Index extends JFrame{
private String title = "This is the motherfucking title";
Dimension dim = new Dimension(500,500);
public Index(){
this.setResizable(false);
this.setTitle(title);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(dim);
this.getContentPane().setBackground(Color.BLACK);
JButton button = new JButton("Button");
button.setSize(200,200);
this.add(button);
}
public static void main(String args[]){
Index ih = new Index();
ih.setVisible(true);
}
}
Here's the result: http://i.imgur.com/Llj0pfo.png
What am I doing wrong?

try this:
JButton button = new JButton("Button");
button.setSize(200,200);
getContentPane().setLayout(null);
getContentPane().add(button);
setVisible(true);
inside your constructor.

this.add(button);
You are adding the button to the content pane of the frame. By default the content uses a BorderLayout and the component is added to the CENTER. Any component added to the CENTER will automatically get the extra space available in the frame. Since you set the size of the frame to (500, 500) there is lots of space available.
As a general rule you should NOT attempt to set the preferred size of a component, since only the component know how big it should be in order to paint itself properly. So your basic code should be:
JButton button = new JButton("...");
frame.add(button);
frame.pack();
frame.setVisible(true);
Now the button will be at its preferred size. However, the button will change size if you resize the frame. If you don't want this behaviour, then you need to use a different Layout Manager.

Use SwingUtilities.invokeLater(); create your Index() inside it, then call setVisible(true); at the end of constructor. At the same time remeber that by default JFrame uses BorderLayout.
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Index();
}
});

Java Swing blank screen instead of window displayed

I'm following through a book called "The JFC Swing Tutorial (Second Edition)" and I'm pretty much at the start I have followed this code and it should be displaying the button and the label in the content pane, but All im getting is a blank screen. any ideas?
Thanks.
import java.awt.GridLayout;
import javax.swing.*;
public class m extends JFrame
{
void UserFrame()
{
//JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Hellow You");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel jp = new JPanel(new GridLayout(0,1));
//makes label
JLabel label = new JLabel("Sup ");
//adds to the frames content pane a label
frame.getContentPane().add(label);
JButton button = new JButton("Hai");
frame.getContentPane().add(button);
jp.add(button);
jp.add(label);
jp.setBorder(BorderFactory.createEmptyBorder(30,30,10,30));
//pack set the window to what it needs AKA to display all components
frame.pack();
//frame.setSize(250, 250);
//shows window
frame.setVisible(true);
}
public static void main(String[] args)
{
final m window = new m();
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
window.UserFrame();
}
});
}
}

Simply add
frame.add(jp);
just before
frame.pack();
What's happening here? You correctly add all your widgets to a JPane, but you basically threw that JPane away and didn't use it anywhere.
This will be sufficient just to get it to work properly.
If you want to do it correctly, you should also remove frame.getContentPane().add(label); and frame.getContentPane().add(button); (Thank you #dic19 for noting that!). These will not work the way you used it.

Advice required in making a simple text editor using the Java Swing Class Library

I am a java beginner and I want to make a simple text editor but I find the following problem. The JTextArea doesn't re-size along with the JFrame. Here is my code :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class textEditor
{
JFrame frame;
JTextArea textArea;
JScrollPane scrollPane;
//JButton button;
public textEditor() //Constructor
{
frame = new JFrame("Title of the frame!");
frame.setLayout(new FlowLayout());
textArea = new JTextArea("");
scrollPane = new JScrollPane(textArea);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
//button = new JButton();
}
public void launchFrame()
{
//Adding Text Area and ScrollPane to the Frame
frame.getContentPane().add(textArea);
frame.getContentPane().add(scrollPane);
//Make the Close button to close the frame when clicked
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Displaying the Frame
frame.setVisible(true);
frame.pack();
}
public static void main(String args[])
{
textEditor window=new textEditor();
window.launchFrame();
}
}
Please don't forget that I'm a beginner so please give me a solution in simple words.

The JTextArea doesn't re-size along with the JFrame as you are using a FlowLayout manager which uses preferred sizes of components instead of expanding them to fill the full space of the container. To fix you can remove the line:
frame.setLayout(new FlowLayout());
JFrame containers use BorderLayout manager by default, which will do the necessary sizing that you are looking for.
Also remove the line
frame.getContentPane().add(textArea);
as only the JScrollPane is required to be added to the frame.