There are two versions of traffic light system. One was created many years ago with JDK1.0.2. The source is included in the ZIP file you should have received. I do not know why you called it partial code? Everything is included in the ZIP file.  Another version was created with EJS. You can find the source code for all the applets created with EJS on this server. Just click "load ejs as signed applet", EJS will be loaded into your browser. You can save the ejs source code, modify the code and generate new applets. Everything can be saved to your local disk. If you like to work with ejs applets. I would suggest you download EJS package and run it locally as an java application. You can work offline if you have installed ejs locally.