private CategoryDataset createDataset() throws Exception {
 
    DefaultCategoryDataset dataset = new DefaultCategoryDataset();
    dataset.addValue(255, "Errors", "error1");
    dataset.addValue(34, "Errors", "error2");
    dataset.addValue(111, "Errors", "error5");
    dataset.addValue(23, "Errors", "error3");
 
    return dataset;
}
 
private JFreeChart createChart(CategoryDataset dataset) {
    // create the chart...
    JFreeChart chart = ChartFactory.createLineChart(
            "Medida", // chart title
            "Error Code", // x axis label
            "Count", // y axis label
            dataset, // data
            PlotOrientation.VERTICAL,
            true, // include legend
            true, // tooltips
            false // urls
    );
 
    return chart;
}