title: java class that simulates a simple database table
body: <p>I have a collection of heterogenous data that I pull from a database table mtable.  Then, for every unique value uv in column A, I compute a function of (SELECT * FROM mtable WHERE A=uv).  Then I do the same for column B, and column C.  There are rather a lot of unique values, so I don't want to hit the db repeatedly - I would rather have a class that replicates some of the functionality (most importantly some version of SELECT WHERE).  Additionally, I would like to abstract the column names away from the class definition, if that makes any sense - the constructor should take a list of names as a parameter, and also, I suppose, a list of types (right now this is just a String[], which seems hacky).  I'm getting the initial data from a RowSet.<br>
  I've more or less done this by using a hashmap that maps Strings to lists/arrays of Objects, but I keep getting bogged down in comparisons and types, and am thinking that my current implementation really isn't as clean and clear as it could be.  I'm pretty new to java, also, and am not sure if I'm not going down a completely incorrect path.
  Does anyone have any suggestions?</p>