Images in the main class (the applet) are easy; see here.

If you are putting them in one of your classes that get called by the applet (or JFrame), its just a little trickier. The class that is used needs to know about that window (called a component).

For example if we had an applet class called Main and a Spaceship class.

In Main when we declare the Spaceship we might:

Spaceship theSpaceship = new SpaceShip(x,y,this);

We have added the word this -> which is referring to this applet. Now the Spaceship (which had parameters x,y) will take in a parameter that is the applet.

In Spaceship our constructor looks like:

	//Globals to keep track of the image and the applet
	Image img;
	Component window; //this window could be either a JFrame or JApplet

	public Spaceship(int x, int y, Component window)
	{
    		this.window=window;
	    //Now I will load the img
	    img = window.getToolkit().getImage(getClass().getResource("liftoff.jpg"));
	}    		
	        

For our drawing method: we need to draw on the window

  
	public void draw(Graphics g)
    {

          g.drawImage(img,200,200,window); 
    }	 
	        

Here is an example:

The Main class:

  
import java.applet.*; 
import java.awt.*;

public class Main extends Applet  
{
    Spaceship theSpaceship;
   	public void init()
	{
    	theSpaceship = new SpaceShip(x,y,this);
	}
    
    public void paint (Graphics g)
    {
         theSpaceship.draw(g);
    }
   
}	

The Spaceship class:

  
import java.awt.*;   
  
public class Spaceship
{
	//Globals to keep track of the image and the applet
	Image img;
	Component window; //this window could be either a JFrame or JApplet

	public Spaceship(int x, int y, Component window)
	{
    	this.window=window;
	    //Now I will load the img
	    img = window.getToolkit().getImage(getClass().getResource("liftoff.jpg"));
	}    
	public void draw(Graphics g)
    {
          g.drawImage(img,200,200,window); 
    }
}