jfree-生成xy图

需要导入的包：

 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;

若是maven工程，需要引入依赖如下：

 <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 );

 }

生成图片如下：