how to write a java program with graphics code example

Example 1: Write a simple java swing application that will display rectangle graphics as shown in the picture below:

Font plainFont = new Font("Serif", Font.PLAIN, 12);
Font bigBoldFont = new Font("SansSerif", Font.BOLD, 24);

Example 2: Write a simple java swing application that will display rectangle graphics as shown in the picture below:

Color myColor = new Color(r,g,b);