import org.jfree.chart.*;

 import org.jfree.chart.plot.PlotOrientation;

 import org.jfree.data.category.DefaultCategoryDataset;

 import org.jfree.data.general.SeriesException;

 import org.jfree.data.time.Second;

 import org.jfree.data.time.TimeSeries;

 import org.jfree.data.time.TimeSeriesCollection;

 import org.jfree.data.xy.XYDataset;

 <dependency>

   <groupId>jfree</groupId>

   <artifactId>jfreechart</artifactId>

   <version>1.0.13</version>

 </dependency>

 /**

 * 生成xy图

 */

 public static void drawXYChart(String imgTitle,String xLable,String yLabel,XYDataset dataset,String imgPath) {

     try {

         JFreeChart timechart = ChartFactory.createTimeSeriesChart(imgTitle, xLable, yLabel,

                 dataset, false, false, false);

 　　　　　//定义图片宽度和高度

         int width = 560;

         int height = 370;

         File timeChart = new File(imgPath);

 　　　　  //图片以JPEG格式保存

         ChartUtilities.saveChartAsJPEG(timeChart, timechart, width, height);

     }catch (Exception e){

         e.printStackTrace();

     }

 }

 public static void main(final String[] args) throws Exception {

 　　final TimeSeries series = new TimeSeries("Random Data");

 　　XYDataset dataset = (XYDataset) new TimeSeriesCollection(series);

    List<Long[]> list = new ArrayList<>();

    list.add(...) //添加一些测试数据来填充list对象

 　　for(Long[] item : list){

       Second current = new Second(new Date(item[0]));

       series.add(current,item[1]);

 　　}

 　　DrawImgUtil.drawXYChart("computing Test","Seconds","Value",dataset, "/Users/test/per/" + imgName );

 }