Java da JFrame i kod ile tam ekrana getirmek için.

 
import java.awt.*; 
import javax.swing.*; 

public class test extends JFrame 
{ 
public test() 
{ 
GraphicsEnvironment env = 
GraphicsEnvironment.getLocalGraphicsEnvironment(); 
this.setMaximizedBounds(env.getMaximumWindowBounds()); 
this.setExtendedState(this.getExtendedState() | this.MAXIMIZED_BOTH); 
} 

public static void main(String[] args) 
{ 
JFrame.setDefaultLookAndFeelDecorated(true); 

test t = new test(); 
t.setVisible(true); 
} 
}