DefaultBoxAndWhiskerCategoryDataset dataset
                = new DefaultBoxAndWhiskerCategoryDataset() {

            public Number getQ1Value(int row, int column) {
                return null;
            }

            public Number getQ1Value(Comparable rowKey, Comparable columnKey) {
                return null;
            }
        };
        List values = new ArrayList();
        values.add(new Double(1.0));
        values.add(new Double(10.0));
        values.add(new Double(100.0));
        dataset.add(values, "row", "column");
        CategoryPlot plot = new CategoryPlot(dataset, new CategoryAxis("x"),
                new NumberAxis("y"), new BoxAndWhiskerRenderer());