Re: method undefined error
First, for future reference post an SSCCE - we do not know what lightQueue is, and where those methods are defined. Second, I would recommend reading the following describing code conventions for the language: Code Conventions for the Java Programming Language I point you to this given the following line of code:
lightQueue lightQueue = new lightQueue();
What is lightQueue? A class, or a variable? How does the compiler (or the programmer) distinguish between the two?