Unable to run Java GUI programs with Ubuntu

Question

I am learning GUI in Java, and for that I have created a demo program:

import java.awt.*;

public class FrameDemo extends Frame {

    public FrameDemo(){
           


        

Answer 1

This command worked for me.

Sudo dnf install java-1.8.0-openjdk (Fedora)

Sudo apt-get install java-1.8.0-openjdk

Should work for Ubuntu.

Answer 2

Use JFrame instead of Frame. And do not extend from JFrame. Just write a class that has a JFrame property named gui, which configures this JFrame with the available methods, because it is better style doing it like this. Extending here is wrong the use of OOP.

Answer 3

I too had OpenJDK on my Ubuntu machine:

$ java -version
java version "1.7.0_51"
OpenJDK Runtime Environment (IcedTea 2.4.4) (7u51-2.4.4-0ubuntu0.13.04.2)
OpenJDK 64-Bit Server VM (build 24.45-b08, mixed mode)

Replacing OpenJDK with the HotSpot VM works fine:

sudo apt-get autoremove openjdk-7-jre-headless

How to install the JDK on Ubuntu (Linux)