checkstyle

All constructors for FileWriter and FileReader should be banned, as they
all use default encoding, and there isn't a default constructor.

There are several overloaded function calls which cannot be distinguished
by name and parameter count alone:
String(byte[]) vs. String(char[]), String(StringBuilder), ...
String(byte[], int, int) vs. String(char[], int, int), String(int[], int,
int)
Scanner(InputStream), Scanner(File), Scanner(ReadableByteChannel) vs.
Scanner(Readable), Scanner(String)

To distinguish these overloaded calls, type information is required. I see
several possibilities:
1. Don't warn about those overloaded functions at all
2. Simple type inference, will give no or wrong answers in some cases
3. Full type inference, will require quite a lot of work
4. Examine class files, not source files, e.g. using BCEL

I'm in favor of #4, as it's the least amount of work, will allow an easy,
straight-forward and robust check, and having a working BCEL framework in
checkstyle would be useful in other cases as well.

As the contributed BCEL code doesn't conform to the checkstyle 5 API, I've
submitted patch #2788019 for it.
https://sourceforge.net/tracker/?func=detail&aid=2788019&group_id=29721&atid=397080
That patch is only a partial solution, though, so some adjustments are yet
required.