jree-创建普通折线图

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) {
         JFreeChart lineChart = ChartFactory.createLineChart(imgTitle, xLabel, yLabel, ds, PlotOrientation.VERTICAL, true, true, false);
         File chart = new File(savingPath);
         try {
             ChartUtilities.saveChartAsPNG(chart, lineChart, width, height);
         } catch (Exception e) {
             System.out.println(ErrorCodeEnum.CREATE_IMAGE_FAILED.getMessage());
             e.printStackTrace();
         }

     }

　　

　　

 //创建数据集对象
    public static   DefaultCategoryDataset getDataSet(){
         DefaultCategoryDataset line_chart_dataset = new DefaultCategoryDataset();
         line_chart_dataset.addValue(15, "schools", "1970");
         line_chart_dataset.addValue(30, "schools", "1980");
         line_chart_dataset.addValue(60, "schools", "1990");
         line_chart_dataset.addValue(120, "schools", "2000");
         line_chart_dataset.addValue(240, "schools", "2010");
         line_chart_dataset.addValue(300, "schools", "2014"); 

         return line_chart_dataset;
 }