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paintComponents method not being called in Java

I watched a tutorial and tried to do same thing, I wrote the codes exactly the same but it shows nothing. I think it is because paintComponent method is not being called, I also tried to print something to console by paintComponent.
Here is my code:
public class Line extends JPanel{
#Override
public void paintComponents(Graphics g){
super.paintComponent(g);
g.setColor(Color.red);
g.drawLine(100, 10, 30, 40);
}
public static void main(String[] args) {
Line l =new Line();
JFrame myFrame = new JFrame("Line");
myFrame.setSize(600, 400);
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.add(l);
myFrame.setVisible(true);
}
}
Thank you!

What you want to override is paintComponent, not paintComponents with a s .
paintComponents paints the child components of the current component (well it sort of tells the child components to paint themselves on the Graphics object).
paintComponent paints the component itself, this is the method you want to override to do custom painting for your component.

Calling the paint() method from another class?

I am trying to call the paint() method from another class, but it just doesn't work.
Here is the code:
Main.java:
public class Main extends JFrame {
private static final long serialVersionUID = 1L;
private int WIDTH = 600;
private int HEIGHT = 400;
private String NAME = "Dark Ages";
private String VERSION = "0.0.1 Pre-Alpha";
static boolean running = false;
private Image dbImage;
private Graphics dbg;
public Main() {
//Initialize window
JFrame frame = new JFrame();
frame.setTitle(NAME + " - " + VERSION);
frame.setSize(WIDTH, HEIGHT);
frame.setVisible(true);
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
//Running
running = true;
}
public void paint(Graphics g) {
dbImage = createImage(getWidth(), getHeight());
dbg = dbImage.getGraphics();
paintComponent(dbg);
g.drawImage(dbImage, 0, 0, this);
}
public void paintComponent(Graphics g) {
// Draw Images
repaint();
}
public static void main(String args[]) {
new Main();
Player player = new Player();
}
}
Player.java:
public class Player {
public void paint(Graphics g) {
g.drawRect(100, 100, 100, 100);
}
}

How do I call the paint() method from another class in java?
In brief, you don't. And in fact, you shouldn't call it directly from the same class either. Instead you should change the state of the class (change its fields), and then call repaint() on it, which will suggest to the JVM that the component should be painted.
Other issues and suggestions:
An obvious issue I see immediately in your code is that your class has a Graphics field, something that is dangerous to do. I suggest that you get rid of that field so that you're not tempted to use it.
Do not draw directly within a JFrame, JDialog or other top-level window. These windows have too many roles to play behind the scenes that you don't really want to mess with how they render themselves or their children (unless you really know what you're doing and have definite need).
Better to draw in the paintComponent(...) method override of a JPanel or other JComponents.
In your paintComponent(...) override, don't forget to call the super's method: super.paintComponent(g);. This will allow Swing to do housekeeping drawing, such as erasing old out of date or deleted images, before you do your drawing.
Run, don't walk to your nearest Swing painting tutorial.
Your current Player class extends no Swing component and is added to no top level window, so its code will do nothing useful. Again, read the tutorials.
Never call repaint() from within paint(...) or paintComponent(...).
Please post modified code if possible.: please don't ask us to create code for you as that's your job. Please understand that the more code you create, the better a coder you'll be, and because of this, most of us don't feel that we should cheat you out of the opportunity to create your own code.
Useful Java Tutorials:
The Really Big Index: The main tutorial where you should start.
Using Swing Components: How to create Swing GUI's
Lesson: Performing Custom Painting: Introductory tutorial to Swing graphics
Painting in AWT and Swing: Advanced tutorial on Swing graphics

Why am I not able to "draw" on my JFrame?

I am trying to draw on my JFrame, but I can't get my super.paintComponents(g); to work. Also, nothing is drawing on my JFrame when I tell it to in my paintComponent() method.
Here is the code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class MTGSAMPServerReference extends JFrame implements ActionListener {
public static Toolkit tk = Toolkit.getDefaultToolkit();
static int ScrnWidth = ((int) tk.getScreenSize().getWidth());
static int ScrnHeight = ((int) tk.getScreenSize().getHeight());
private static final long serialVersionUID = 1L;
private static JList list1;
private static JButton next;
public MTGSAMPServerReference() {
// set flow layout for the frame
this.getContentPane().setLayout(new FlowLayout(FlowLayout.LEADING));
Object[]mainData = {"Vehicles", "Bikes/Bicycles", "Boats", "Houses", "Businesses", "Objects", "Jobs", "Ranks", "Licenses", "VIP"};
JPanel controls = new JPanel(new BorderLayout(5,5));
list1 = new JList<Object>(mainData);
list1.setVisibleRowCount(10);
next = new JButton("Next");
next.addActionListener(this);
controls.add(new JScrollPane(list1));
controls.add(next, BorderLayout.PAGE_END);
controls.setBorder(new EmptyBorder(25,25,0,0));
add(controls);
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Next")) {
int index = list1.getSelectedIndex();
System.out.println("Index Selected: " + index);
String s = (String) list1.getSelectedValue();
System.out.println("Value Selected: " + s);
}
}
public void createAndShowGUI() {
//Create and set up the window.
JFrame f = new MTGSAMPServerReference();
//Display the window.
f.pack();
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(1200, 800);
f.setLocationRelativeTo(null);
list1.setSize(250, 250);
list1.setLocation(0, 0);
next.setSize(75, 25);
next.setLocation(251, 276);
MTGSAMPServerReference.this.repaint();
}
protected void paintComponent(Graphics g) {
//super.paintComponent(g); << Can't seem to get this to work.
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.drawRect(0, 0, 50, 50);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
MTGSAMPServerReference gui = new MTGSAMPServerReference();
gui.createAndShowGUI();
}
});
}
}
I have worked with paintComponent() before, but still can't seem to figure out what I am doing wrong. I know that it has got to be a simple fix, but can't spot it for the life of me. Any ideas?
Any and all help is appreciated.
Thanks in advance!

Use the #Override annotation on your paintComponent method for a rude surprise. This is why using this annotation is very helpful, since it will flag you at compile time if you are not overriding a method when you think that you should be.
Solution: never "paint" in a JFrame for many reasons. Instead do what the tutorials tell you to do -- paint in a JPanel or JComponent's paintComponent(...) method. If you search this site you will find that we have told many folks here the same thing, and in fact I suggest that you do just that. I wouldn't be surprised if this question is closed as a duplicate since this is a fairly common question.
Note this won't "work" (and actually won't compile):
super.paintComponent(g); << Can't seem to get this to work.
for the same reason -- there is no super.paintComponent(g) for a JFrame.
Also, regarding,
I have worked with paintComponent() before, but still can't seem to figure out what I am doing wrong.
But if you look at your prior code, you'll see that this method was never used directly in a JFrame, and nor should it.

paintComponent() is a member of the JPanel class, not the JFrame class in which you are trying to call it.
That is why you are unable to call super.paintComponent(Graphics g). The compiler thinks you are creating your own completely unrelated method that also happens to be called paintComponent().
Create a class that inherits JPanel and copy and paster your paintComponent() method there.
Like Hovercraft Full Of Eels commented, you can check that you are correctly overriding methods by adding the #Override tag directly over the method header; if you receive an error, you are doing something wrong.
For more information about JPanel and JFrame, see my answer to this question.

Java drawn objects not updating properly

I have been playing around with Java's 2d painting tools and have hit a snag. I am attempting to move the objects. Here is the code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Test extends JPanel{
private int[] location = new int[2];
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.red);
g.fillArc(location[0], location[1], 100, 100, 45, 90);
g.setColor(Color.black);
g.fillArc((location[0]+50-10),(location[1]+50-10), 20, 20, 0, 360);
new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
setLocation((location[0]+50),50);
repaint();
System.out.println("repainting");
}
}).start();
}
public void setLocation(int x, int y){
this.location[0] = x;
this.location[1] = y;
}
public static void main(String[] args){
JFrame jf=new JFrame();
jf.setDefaultCloseOperation
(JFrame.EXIT_ON_CLOSE);
jf.setPreferredSize(new Dimension(300,500));
jf.setLocation(100,100);
jf.add(new Test());
jf.pack();
jf.setVisible(true);
}
}
This only paints one of the two objects to the screen... it seems to be the second one as when I change the parameters of setLocation on [1] the one object it does paint moves. Any thoughts? Thanks
Edit: Edited above code to reflect what was said below.

You are adding two components to the JFrame in a default way. This will add the components BorderLayout.CENTER and so the second component will cover and obscure the first. You will want to read up on layout managers to fix this. Also read up on Swing Timers for simple animations, since your code, even if written correctly would do no animation.
If you want to move the drawing, then
Use only one Test JPanel
Override JPanel's paintComponent(...) method, not paint(...) method.
call the super.paintComponent(g) method first thing in your paintComponent method override.
Give the Test JPanel public methods to allow outside classes to change the location without having them directly futz with the field. Make the location field (name should begin with a lower-case letter) private just to be safe.
Use a Swing Timer to periodically call this method and change location, then call repaint() on the JPanel.

Can't paint on directly on JFrame

I have an assignment to create a paint program in Java. I have managed to create something but not exactly what I wanted.
My problem is that I cannot create a JFrame in my IDE(NetBeans 7.0.1) from the options that the IDE gives me, and call the paint classes correctly.
To be more specific I want to press a button from one panel(ex. Panel1) and paint in Panel2,in the same frame.
That's the calling of the class:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
PaintFlower102 f = new PaintFlower102();
}
Part of Class:
super("Drag to Paint");
getContentPane().add(new Label ("Click and Drag"),BorderLayout.SOUTH);
// add(new JButton("Brush 20"),BorderLayout.NORTH);
addMouseMotionListener( new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent event) {
xval=event.getX();
yval=event.getY();
repaint();
}
});
setSize(500, 500);
setVisible(true);
setDefaultCloseOperation(PaintFlower102.DISPOSE_ON_CLOSE);
}
public void paint(Graphics g) {
g.fillOval(xval, yval, 10, 10);
}
The problem is that if I do not put the extend JFrame in the class this doesn't work. And if I do, it creates a new frame in which I can draw.

Suggestions:
Don't ever paint directly in a JFrame except under rare circumstances of absolute need (this isn't one of them).
Instead paint in a JPanel or JComponent or other derivative of JComponent.
Paint in the class's paintComponent(Graphics g) method, not in paint(Graphics g).
Read the Java tutorials on this as it's all explained well there. Check out Trail: 2D Graphics and Performing Custom Painting.

I might be wrong, but I think that you need to include super.paintComponent(g), and override the paintComponent method like Hovercraft Full Of Eels said.
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Draw Oval
g.fillOval(xval, yval, 10, 10);
}