Install openjdk

See http://openjdk.java.net/install/. On Ubuntu, I can use

sudo apt-get install openjdk-7-jdk

Some projects written in Java

FastQC The code uses Java 2D graphics APIs in awt like BasicStroke, Color, Dimension, Graphics, Graphics2D, RenderingHints and javax.swing.JPanel. It also uses java.util.Vector.

Tutorial

Compile a simple Java program

javac Example.java # generate Example.class; bytecode version of the program
java Example   # run bytecode in Java Virtual Machine

Swing

http://zetcode.com/tutorials/javaswingtutorial/

For example, use 'nano SimpleExample.java' to create a new file

package com.zetcode;

import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class SimpleExample extends JFrame {

    public SimpleExample() {
        
       setTitle("Simple example");
       setSize(300, 200);
       setLocationRelativeTo(null);
       setDefaultCloseOperation(EXIT_ON_CLOSE);        
    }
    

    public static void main(String[] args) {
        
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                SimpleExample ex = new SimpleExample();
                ex.setVisible(true);
            }
        });
    }
}

Then

javac SimpleExample.java # generate SimpleExamples.class and SimpleExample$1.class