I suggest that you stop focusing only on "Java." There are many, many other software development positions that have nothing to do with Java. Since on you state the you have .NET experience, then you should also be looking for .NET jobs as well as studying .NET material. I think this approach will help you find a "job" faster than if you only focuson Java and spend "waste" time trying to find an open-source project or some sort of programming community service.
Are you still in college?
Companies don't general expect entry level people to have real world experience.
Also, you said the board size is configurable. If the board size is 5x5, do they need three in a row or five in a row?
4) Why do you catch Exception? Are you expecting something to go wrong?