Re: Re-using an existing db and archiving data

[Jørgen Løland]

Mark Hiles wrote:

Based on what I've read, I'm not going to get the number of results and store in
an array, I'll just use 2 ArrayLists instead..

I'm still getting my null pointer exception for some reason. It must be
happening inside the rs.next() method when I call it..

My code looks something like this:

rs = stmt.executeQuery("...");

while(rs.next()) {

    arrLstS.add(rs.getString("..."));
    arrLstS.add(getRoomName(rs.getInt("...")));

arrLstB.add(rows); }

I caught the exception and did a stack trace but all it said was:

java.lang.NullPointerException
        at dbcon.DBCon.getReadings(DBCon.java:308)
        at dbcon.DBCon.<init>(LocalDBConnection.java:58)
        at dbcon.DBCon.LocalDBConnection.main(LocalDBConnection.java:39)

I've put in some test data and the SQL query should return 2 results. But even
if it didn't return any results, my code just wouldn't go into the while loop. I
don't see why I'm getting a null pointer exception.

And what happens on line 308 in your DBCon.java file?


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Jørgen Løland