Receiving a null pointer exception when trying to use toString

Question

I am trying to access a local database and pull the data out and store it in an array...but I keep receiving a null pointer exception, please help?

int rows = 0;
int colNum = res.getMetaData().getColumnCount();
res.beforeFirst();

while(res.next()){
    rows++;
    for(int i = 1; i < colNum; i++){
        teamTable[rows - 1][colNum - 1] = res.getString("Team");
        teamTable[rows - 1][colNum - 1] = res.getInt("Goal Difference");
        teamTable[rows - 1][colNum - 1] = res.getInt("Points");
        System.out.println(teamTable[rows - 1][colNum - 1]);
    }
}

please show the stack trace, and indicate the line of your sample code to which the line number in the stack trace refers. — GreyBeardedGeek, Sep 29 '13 at 22:26
Exception in thread "main" java.lang.NullPointerException at TheDatabaseConnecter.main(TheDatabaseConnecter.java:46) — Daniel Buckle, Sep 29 '13 at 22:30
Please copy-paste your whole .java file (as short as possible) and the whole stack trace. — pts, Sep 29 '13 at 22:34

score 0 · Accepted Answer · edited May 23 '17 at 10:32

My bet is that you haven't initialized the teamTable multidimensional array properly. Does it have enough rows? Have you called teamTable[rowIndex] = new Object[colNum];? If you forgot about the second one, or teamTable is just null, then you get a NullPointerException.

If this isn't clear, then read a tutorial about Java multidimensional arrays, e.g. the answers for this question: Syntax for creating a two-dimensional array

Receiving a null pointer exception when trying to use toString

1 Answers1