this is my code:
Shape RADAR = builder.insertChart(ChartType.COLUMN, 300, 300);
Chart chart = RADAR.getChart();
ChartSeriesCollection series = chart.getSeries();
series.clear();
String mark="mark";
String[] categories = new String[] { "others","one","two","three","four","five" };
double[] values = new double[] { 99,90,94,97,98,99};
series.add("mark", categories, values);
Iterator it = series.iterator();
ChartDataLabelCollection dataLabels = null;
ChartDataLabel chartdatalabel = null;
while (it.hasNext()) {
ChartSeries chartseries = it.next();
dataLabels = chartseries.getDataLabels();
dataLabels.clear();
dataLabels.add(0);
dataLabels.get(0).setShowValue(true);
}