cleanup

Just some clean up stuff including:
- removing unnecessary imports (some of the imports for classes were changed to single class imports, even though i prefer it that way, but tried to avoid doing this as it would make the diff messier, but sometimes it still happened due to my IDE)
- removing unnecessary casting
- removing unnecessary logic checks
- removing unused variables
Rather than removing queryStatement, either change all statements to queryStatement, removing the declaration, or change queryStatement to statement, still removing the new statement declaration in the try block