在平时涉及到数据分析以及画图一般都是用MATLAB或者Python，在这两个之中都有封装好的库，可以直接使用造好的轮子。而在Java中自带jar包并没有相关功能，需要导入外部包
- jfreechart-1.0.13.jar
- jcommon-1.0.16.jar
- gnujaxp.jar
运行结果如下图
柱形图1代码段
package com.njue.testJFreeChart;
import java.awt.Font;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
public class BarChart {
ChartPanel frame1;
public BarChart(){
CategoryDataset dataset = getDataSet();
JFreeChart chart = ChartFactory.createBarChart3D(
"共享单车", // 图表标题
"单车种类", // 目录轴的显示标签
"数量", // 数值轴的显示标签
dataset, // 数据集
PlotOrientation.VERTICAL, // 图表方向：水平、垂直
true, // 是否显示图例(对于简单的柱状图必须是false)
false, // 是否生成工具
false // 是否生成URL链接
);
//从这里开始
CategoryPlot plot=chart.getCategoryPlot();//获取图表区域对象
CategoryAxis domainAxis=plot.getDomainAxis(); //水平底部列表
domainAxis.setLabelFont(new Font("黑体",Font.BOLD,14)); //水平底部标题
domainAxis.setTickLabelFont(new Font("宋体",Font.BOLD,12)); //垂直标题
ValueAxis rangeAxis=plot.getRangeAxis();//获取柱状
rangeAxis.setLabelFont(new Font("黑体",Font.BOLD,15));
chart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 15));
chart.getTitle().setFont(new Font("宋体",Font.BOLD,20));//设置标题字体
//到这里结束，虽然代码有点多，但只为一个目的，解决汉字乱码问题
frame1=new ChartPanel(chart,true); //这里也可以用chartFrame,可以直接生成一个独立的Frame
}
private static CategoryDataset getDataSet() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(100, "北京", "ofo");
dataset.addValue(100, "上海", "ofo");
dataset.addValue(100, "广州", "ofo");
dataset.addValue(200, "北京", "酷奇");
dataset.addValue(200, "上海", "酷奇");
dataset.addValue(200, "广州", "酷奇");
dataset.addValue(300, "北京", "青桔");
dataset.addValue(300, "上海", "青桔");
dataset.addValue(300, "广州", "青桔");
dataset.addValue(400, "北京", "摩拜");
dataset.addValue(400, "上海", "摩拜");
dataset.addValue(400, "广州", "摩拜");
dataset.addValue(500, "北京", "二八大杠");
dataset.addValue(500, "上海", "二八大杠");
dataset.addValue(500, "广州", "二八大杠");
return dataset;
}
public ChartPanel getChartPanel(){
return frame1;
}
}
柱形图2代码段
package com.njue.testJFreeChart;
import java.awt.Font;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
//这是柱形图的另一种效果，其实跟第一种相比都只有数据集发生了变化，再无其他变化
public class BarChart1 {
ChartPanel frame1;
public BarChart1(){
CategoryDataset dataset = getDataSet();
JFreeChart chart = ChartFactory.createBarChart3D(
"共享单车", // 图表标题
"共享单车种类", // 目录轴的显示标签
"数量", // 数值轴的显示标签
dataset, // 数据集
PlotOrientation.VERTICAL, // 图表方向：水平、垂直
true, // 是否显示图例(对于简单的柱状图必须是false)
false, // 是否生成工具
false // 是否生成URL链接
);
//从这里开始
CategoryPlot plot=chart.getCategoryPlot();//获取图表区域对象
CategoryAxis domainAxis=plot.getDomainAxis(); //水平底部列表
domainAxis.setLabelFont(new Font("黑体",Font.BOLD,14)); //水平底部标题
domainAxis.setTickLabelFont(new Font("宋体",Font.BOLD,12)); //垂直标题
ValueAxis rangeAxis=plot.getRangeAxis();//获取柱状
rangeAxis.setLabelFont(new Font("黑体",Font.BOLD,15));
chart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 15));
chart.getTitle().setFont(new Font("宋体",Font.BOLD,20));//设置标题字体
//到这里结束，虽然代码有点多，但只为一个目的，解决汉字乱码问题
frame1=new ChartPanel(chart,true); //这里也可以用chartFrame,可以直接生成一个独立的Frame
}
private static CategoryDataset getDataSet() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(100, "ofo", "ofo");
dataset.addValue(200, "酷奇", "酷奇");
dataset.addValue(300, "青桔", "青桔");
dataset.addValue(400, "摩拜", "摩拜");
dataset.addValue(500, "二八大杠", "二八大杠");
return dataset;
}
public ChartPanel getChartPanel(){
return frame1;
}
}
饼形图代码段
package com.njue.testJFreeChart;
import java.awt.Font;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import javax.swing.JPanel;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.general.DefaultPieDataset;
public class PieChart {
ChartPanel frame1;
public PieChart(){
DefaultPieDataset data = getDataSet();
JFreeChart chart = ChartFactory.createPieChart3D("单车数量",data,true,false,false);
//设置百分比
PiePlot pieplot = (PiePlot) chart.getPlot();
DecimalFormat df = new DecimalFormat("0.00%");//获得一个DecimalFormat对象，主要是设置小数问题
NumberFormat nf = NumberFormat.getNumberInstance();//获得一个NumberFormat对象
StandardPieSectionLabelGenerator sp1 = new StandardPieSectionLabelGenerator("{0} {2}", nf, df);//获得StandardPieSectionLabelGenerator对象
pieplot.setLabelGenerator(sp1);//设置饼图显示百分比
//没有数据的时候显示的内容
pieplot.setNoDataMessage("无数据显示");
pieplot.setCircular(false);
pieplot.setLabelGap(0.02D);
pieplot.setIgnoreNullValues(true);//设置不显示空值
pieplot.setIgnoreZeroValues(true);//设置不显示负值
frame1=new ChartPanel (chart,true);
chart.getTitle().setFont(new Font("宋体",Font.BOLD,20));//设置标题字体
PiePlot piePlot= (PiePlot) chart.getPlot();//获取图表区域对象
piePlot.setLabelFont(new Font("宋体",Font.BOLD,10));//解决乱码
chart.getLegend().setItemFont(new Font("黑体",Font.BOLD,10));
}
private static DefaultPieDataset getDataSet() {
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("ofo",100);
dataset.setValue("酷奇",200);
dataset.setValue("摩拜",300);
dataset.setValue("青桔",400);
dataset.setValue("二八大杠",500);
return dataset;
}
public ChartPanel getChartPanel(){
return frame1;
}
}
还有折线图代码段
package com.njue.testJFreeChart;
import java.awt.Font;
import java.text.SimpleDateFormat;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.time.Month;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
public class TimeSeriesChart {
ChartPanel frame1;
public TimeSeriesChart(){
XYDataset xydataset = createDataset();
JFreeChart jfreechart = ChartFactory.createTimeSeriesChart("Legal & General单位信托基金价格", "日期", "价格",xydataset, true, true, true);
XYPlot xyplot = (XYPlot) jfreechart.getPlot();
DateAxis dateaxis = (DateAxis) xyplot.getDomainAxis();
dateaxis.setDateFormatOverride(new SimpleDateFormat("MMM-yyyy"));
frame1=new ChartPanel(jfreechart,true);
dateaxis.setLabelFont(new Font("黑体",Font.BOLD,14)); //水平底部标题
dateaxis.setTickLabelFont(new Font("宋体",Font.BOLD,12)); //垂直标题
ValueAxis rangeAxis=xyplot.getRangeAxis();//获取柱状
rangeAxis.setLabelFont(new Font("黑体",Font.BOLD,15));
jfreechart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 15));
jfreechart.getTitle().setFont(new Font("宋体",Font.BOLD,20));//设置标题字体
}
private static XYDataset createDataset() { //这个数据集有点多，但都不难理解
TimeSeries timeseries = new TimeSeries("legal & general欧洲指数信任",
org.jfree.data.time.Month.class);
timeseries.add(new Month(2, 2001), 181.80000000000001D);
timeseries.add(new Month(3, 2001), 167.30000000000001D);
timeseries.add(new Month(4, 2001), 153.80000000000001D);
timeseries.add(new Month(5, 2001), 167.59999999999999D);
timeseries.add(new Month(6, 2001), 158.80000000000001D);
timeseries.add(new Month(7, 2001), 148.30000000000001D);
timeseries.add(new Month(8, 2001), 153.90000000000001D);
timeseries.add(new Month(9, 2001), 142.69999999999999D);
timeseries.add(new Month(10, 2001), 123.2D);
timeseries.add(new Month(11, 2001), 131.80000000000001D);
timeseries.add(new Month(12, 2001), 139.59999999999999D);
timeseries.add(new Month(1, 2002), 142.90000000000001D);
timeseries.add(new Month(2, 2002), 138.69999999999999D);
timeseries.add(new Month(3, 2002), 137.30000000000001D);
timeseries.add(new Month(4, 2002), 143.90000000000001D);
timeseries.add(new Month(5, 2002), 139.80000000000001D);
timeseries.add(new Month(6, 2002), 137D);
timeseries.add(new Month(7, 2002), 132.80000000000001D);
TimeSeries timeseries1 = new TimeSeries("legal & general英国指数信任",
org.jfree.data.time.Month.class);
timeseries1.add(new Month(2, 2001), 129.59999999999999D);
timeseries1.add(new Month(3, 2001), 123.2D);
timeseries1.add(new Month(4, 2001), 117.2D);
timeseries1.add(new Month(5, 2001), 124.09999999999999D);
timeseries1.add(new Month(6, 2001), 122.59999999999999D);
timeseries1.add(new Month(7, 2001), 119.2D);
timeseries1.add(new Month(8, 2001), 116.5D);
timeseries1.add(new Month(9, 2001), 112.7D);
timeseries1.add(new Month(10, 2001), 101.5D);
timeseries1.add(new Month(11, 2001), 106.09999999999999D);
timeseries1.add(new Month(12, 2001), 110.3D);
timeseries1.add(new Month(1, 2002), 111.7D);
timeseries1.add(new Month(2, 2002), 111D);
timeseries1.add(new Month(3, 2002), 109.59999999999999D);
timeseries1.add(new Month(4, 2002), 113.2D);
timeseries1.add(new Month(5, 2002), 111.59999999999999D);
timeseries1.add(new Month(6, 2002), 108.8D);
timeseries1.add(new Month(7, 2002), 101.59999999999999D);
TimeSeriesCollection timeseriescollection = new TimeSeriesCollection();
timeseriescollection.addSeries(timeseries);
timeseriescollection.addSeries(timeseries1);
return timeseriescollection;
}
public ChartPanel getChartPanel(){
return frame1;
}
}
最后在主方法中将其调用
package com.njue.testJFreeChart;
import java.awt.GridLayout;
import javax.swing.JFrame;
public class mainClass {
public static void main(String args[]){
JFrame frame=new JFrame("共享单车数据统计图");
frame.setLayout(new GridLayout(2,2,10,10));
frame.add(new BarChart().getChartPanel()); //添加柱形图
frame.add(new BarChart1().getChartPanel()); //添加柱形图的另一种效果
frame.add(new PieChart().getChartPanel()); //添加饼状图
frame.add(new TimeSeriesChart().getChartPanel()); //添加折线图
frame.setBounds(50, 50, 800, 600);
frame.setVisible(true);
}
}
本文大部分来自于转载，很多技术细节已经标记在注释之中