对于maven工程，需要引入依赖：
在pom.xml中，添加如下内容

<dependency>
  <groupId>jfree</groupId>
  <artifactId>jfreechart</artifactId>
  <version>1.0.13</version>
</dependency>

　　/**生成普通折线图
   * @param imgTitle  图片的title
　　* @param xLabel x轴标签
　　* @param yLabel y轴标签
　　/
 1 public static void drawPNG(DefaultCategoryDataset ds, String savingPath, String imgTitle, String xLabel, String yLabel, int width, int height) {
 2         JFreeChart lineChart = ChartFactory.createLineChart(imgTitle, xLabel, yLabel, ds, PlotOrientation.VERTICAL, true, true, false);
 3         File chart = new File(savingPath);
 4         try {
 5             ChartUtilities.saveChartAsPNG(chart, lineChart, width, height);
 6         } catch (Exception e) {
 7             System.out.println(ErrorCodeEnum.CREATE_IMAGE_FAILED.getMessage());
 8             e.printStackTrace();
 9         }
10 
11     }

　　

 1 //创建数据集对象
 2    public static   DefaultCategoryDataset getDataSet(){   
 3         DefaultCategoryDataset line_chart_dataset = new DefaultCategoryDataset();
 4         line_chart_dataset.addValue(15, "schools", "1970");
 5         line_chart_dataset.addValue(30, "schools", "1980");
 6         line_chart_dataset.addValue(60, "schools", "1990");
 7         line_chart_dataset.addValue(120, "schools", "2000");
 8         line_chart_dataset.addValue(240, "schools", "2010");
 9         line_chart_dataset.addValue(300, "schools", "2014"); 
10         
11         return line_chart_dataset;
12 }