DoodlePad is written using the features of Java 8, so it is important that you have at least the Standard Edition (SE) of Java 8 or later installed on your computer, To determine which version of Java that you have installed on your machine, on Windows open a Command Prompt, on MacOS or Linux open a terminal, and type the following.
javac -version
If the Java 8 JDK is installed you will see something like,
javac 1.8.X_XX
If you do not have Java 8 installed, visit Oracle and download the latest Java Developer Kit (JDK) for your operation system. It is important to get the JDK and not the JRE (Java Runtime Environment).
One way to write Java programs is to use a simple editor capable of saving text files. On Windows, Notepad is one option, but a better choice is Notepad++. On the Mac consider TextWrangler or TextMate. As long as your editor saves plain text files you can use it for writing programs.
Even better than a plain text editor is one of many great development environments designed for educational purposes. Two good examples are BlueJ and DrJava. These cross-platform environments will help you create projects, edit and debug your code. Consider downloading one of these excellent tools for your DoodlePad programing.
You'll need to get the doodlepad.jar file. All of DoodlePad is included in this single file. Click here to download doodlepad.jar and save it to your computer.
The next step is to open a new file and write your first program. For now let's enter the program introduced in About DoodlePad, as follows.
import doodlepad.*;
public class MyFirstOval {
public static void main(String[] args) {
Oval oval1 = new Oval();
}
}
When ready, save your program to a file with the name of your class and the ".java" extension. For example, the above program should be saved to a file named "MyFirstOval.java" and then follow the instructions in Compile and Run.
Have a look at the links under Topics for more information on the many things you can do with DoodlePad.