最近项目增加了需求，想要下载折线图和柱状图结合的综合图。我查了一会儿，要实现这个功能，我使用了这两个第三方包了：
jfreechart-1.0.19.jarjcommon-1.0.23.jar
效果：
步骤：
①、导入其相应的 jcommon-1.0.23.jar和 jfreechart-1.0.19.jar文件
②、下面就可以写实现功能的代码了
import java.awt.Color;import java.awt.Font;import java.io.File;import java.io.IOException;import org.jfree.chart.ChartFactory;import org.jfree.chart.ChartFrame;import org.jfree.chart.ChartUtilities;import org.jfree.chart.JFreeChart;import org.jfree.chart.axis.CategoryAxis3D;import org.jfree.chart.axis.CategoryLabelPositions;import org.jfree.chart.axis.NumberAxis3D;import org.jfree.chart.axis.NumberTickUnit;import org.jfree.chart.labels.StandardCategoryItemLabelGenerator;import org.jfree.chart.labels.StandardCategoryToolTipGenerator;import org.jfree.chart.plot.CategoryPlot;import org.jfree.chart.plot.DatasetRenderingOrder;import org.jfree.chart.plot.PlotOrientation;import org.jfree.chart.renderer.category.BarRenderer3D;import org.jfree.chart.renderer.category.LineAndShapeRenderer;import org.jfree.data.category.DefaultCategoryDataset;public class test {public static void main(String[] args) {//折线图数据DefaultCategoryDataset lineDataset = new DefaultCategoryDataset();//添加数据lineDataset.addValue(9, "", "语文");lineDataset.addValue(7, "", "数学");lineDataset.addValue(6, "", "英语");lineDataset.addValue(4, "", "物理");lineDataset.addValue(3, "", "化学");lineDataset.addValue(2, "", "生物");//柱状图数据DefaultCategoryDataset dataset = new DefaultCategoryDataset();//添加数据dataset.addValue(4, "", "语文");dataset.addValue(7, "", "数学");dataset.addValue(6, "", "英语");dataset.addValue(5, "", "物理");dataset.addValue(3, "", "化学");dataset.addValue(9, "", "生物");//生成的柱状图JFreeChart chart = ChartFactory.createBarChart3D("科目成绩","科目",//X轴的标签 "分数",//Y轴的标签 dataset, //图标显示的数据集合PlotOrientation.VERTICAL, //图像的显示形式（水平或者垂直）false,//是否显示子标题 false,//是否生成提示的标签 false); //是否生成URL链接/** 处理图形上的乱码*///处理主标题的乱码chart.getTitle().setFont(new Font("黑体",Font.BOLD,18));//获取图表区域对象CategoryPlot categoryPlot = (CategoryPlot)chart.getPlot();//获取X轴的对象CategoryAxis3D categoryAxis3D = (CategoryAxis3D)categoryPlot.getDomainAxis();//获取Y轴的对象NumberAxis3D numberAxis3D = (NumberAxis3D)categoryPlot.getRangeAxis();//处理X轴上的乱码categoryAxis3D.setTickLabelFont(new Font("黑体",Font.BOLD,10));//处理X轴外的乱码categoryAxis3D.setLabelFont(new Font("黑体",Font.BOLD,10));//处理Y轴上的乱码numberAxis3D.setTickLabelFont(new Font("黑体",Font.BOLD,10));//处理Y轴外的乱码numberAxis3D.setLabelFont(new Font("黑体",Font.BOLD,10));//自定义Y轴上显示的刻度，以10作为1格numberAxis3D.setAutoTickUnitSelection(false);NumberTickUnit unit = new NumberTickUnit(1); numberAxis3D.setTickUnit(unit);//获取绘图区域对象BarRenderer3D barRenderer3D = (BarRenderer3D)categoryPlot.getRenderer();//设置柱形图的宽度barRenderer3D.setMaximumBarWidth(0.07);//在图形上显示数字barRenderer3D.setBaseItemLabelGenerator(new StandardCategoryItemLabelGenerator());barRenderer3D.setBaseItemLabelsVisible(true);barRenderer3D.setBaseItemLabelFont(new Font("宋体",Font.BOLD,10));/** 放折线图数据*/categoryPlot.setDataset(1, lineDataset);//设置折线LineAndShapeRenderer lineandshaperenderer = new LineAndShapeRenderer();lineandshaperenderer.setToolTipGenerator(new StandardCategoryToolTipGenerator());categoryPlot.setRenderer(1, lineandshaperenderer);// 柱状图和纵轴紧靠categoryAxis3D.setLowerMargin(0.0); categoryAxis3D.setCategoryLabelPositions(CategoryLabelPositions.DOWN_45);//折线在柱面前面显示categoryPlot.setDatasetRenderingOrder(DatasetRenderingOrder.FORWARD);/** 在E盘目录下生成图片*/File file = new File("e:\\a.png");try {ChartUtilities.saveChartAsJPEG(file, chart, 800, 600);} catch (IOException e) {e.printStackTrace();}}}
