In Java -

Part 1 - Improve the output quality of the investment application in Section 10.3.2. Format the numbers with two decimal digits, using the String.format method. Set the font of the text area to a fixed width font, using the call

textArea.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 12));

Part 2 - Add error handling to the program in Section 10.3.2. If the interest rate is not a floating-point number, or if it less than 0, display an error message, using a JOptionPane (see Special Topic 2.5).

PLEASE USE JAVADOC AND CODE COMMENT

PLEASE INDICATE HOW MANY CLASSES OR PACKAGES SHOULD BE CREATED. Appreciate if you could include images of your code. I use Eclipse

Here is the code: