JFreeChart Java stopped working error

Question

I am running a sql query and storing the results in a dataset. I am trying to put the results in a pie chart, but I only get the first row of results in the query to print and then Java stops working. I only get this error when I have this line of code in

ChartUtilities.saveChartAsJPEG(new File(filename), piechart, 500, 300);

I have inserted debug statements to make sure that I am storing all rows in the dataset. That works, and I can print them out to the screen; but when I try to save to the file, I get the error.

Here is my code.

String areatext = rs.getString("sum"); 
//System.out.println(areatext);
String depttext = rs.getString("dept");
System.out.println(depttext);
double area = Double.parseDouble(areatext);
System.out.println(area);
dataset.setValue(depttext, area);
System.out.println(dataset);
JFreeChart piechart = ChartFactory.createPieChart(  
        "test",   // Title  
        dataset,             // Dataset  
        true,                   // Show legend  
        true,                   // Use tooltips  
        false                   // Generate URLs  
    ); 
String filename = "c:piechart.jpg";  
try {
    ChartUtilities.saveChartAsJPEG(new File(filename), piechart, 500, 300);
} catch (IOException e) {
    e.printStackTrace();
}