[JAVA] Making a JFrame

package something; //Package name replaces "something"

import javax.swing.JFrame; //So the JFrame can be resolved to a type

public class whatever { //Class name replaces "whatever"
    public static void main(String [] args) {
        JFrame frame = new JFrame("My JFrame");
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 200); //Size can be adjusted
    }
}