As an aside, there is only one class involved in your examples: java.lang.String. What you have several of are objects, all being instances of that single class.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus