Description:
Getting a NullPointerException at
com.mysql.jdbc.ResultSetMetaData.getColumnCount(ResultSetMetaData.java:315)

How to repeat:
The code that causes this is roughly:

PreparedStatement ps = con.prepareStatement(query);
//ps.setObject(i+1, args[i]);
ResultSet rs = ps.executeQuery();
ResultSetMetaData md = rs.getMetaData();
colLen = md.getColumnCount();

Unfortunately your rough code doesn't make this repeatable (just checked, I don't get a
null pointer exception with that code).

My guess is you're calling getMetaData() _after_ the result set has been closed? (either
explicitly, or implicitly by closing the statement that created it, or executing another
query on the same statement?).

I will add a check so that you get the _correct_ exception, but you will now see a 'Result
set closed' exception.

Right you are, it was being closed in a try-finally, on this bug and the last relating to
PreparedStatement. My Aplogies, and thank you. Case closed.