JFreeChart主要用来各种各样的图表，这些图表包括：饼图、柱状图(普通柱状图以及堆栈柱状图)、线图、区域图、分布图、混合图、甘特图以及一些仪表盘等等
(源代码下载)
示例程序运用的jar包：
- jcommon-1.0.17.jar
- jfreechart-1.0.14.jar
1:普通柱状图
这是程序调用CategoryDataset dataset = getDataSet2(); 后所生产的图片
BarChartDemo.java柱状图代码
/**
* 该类用于演示最简单的柱状图生成
* @author Winter Lau
*/
public class BarChartDemo {
public static void main(String[] args) throws IOException{
CategoryDataset dataset = getDataSet2();
JFreeChart chart = ChartFactory.createBarChart3D(
"水果产量图", // 图表标题
"水果", // 目录轴的显示标签
"产量", // 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
);
//中文乱码
CategoryPlot categoryplot = (CategoryPlot) chart.getPlot();
NumberAxis numberaxis = (NumberAxis) categoryplot.getRangeAxis();
CategoryAxis domainAxis = categoryplot.getDomainAxis();
TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体", Font.PLAIN, 20));
domainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));
domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));
numberaxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));
numberaxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));
chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
FileOutputStream fos_jpg = null;
try {
fos_jpg = new FileOutputStream("D:\\BarChart.jpg");
ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f,chart,400,300,null);
} finally {
try {
fos_jpg.close();
} catch (Exception e) {}
}
}
/**
* 获取一个演示用的简单数据集对象
* @return
*/
private static CategoryDataset getDataSet() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(100, "", "苹果");
dataset.addValue(200, "", "梨子");
dataset.addValue(300, "", "葡萄");
dataset.addValue(400, "", "香蕉");
dataset.addValue(500, "", "荔枝");
return dataset;
}
/**
* 获取一个演示用的组合数据集对象
* @return
*/
private static CategoryDataset getDataSet2() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(100, "北京", "苹果");
dataset.addValue(100, "上海", "苹果");
dataset.addValue(100, "广州", "苹果");
dataset.addValue(200, "北京", "梨子");
dataset.addValue(200, "上海", "梨子");
dataset.addValue(200, "广州", "梨子");
dataset.addValue(300, "北京", "葡萄");
dataset.addValue(300, "上海", "葡萄");
dataset.addValue(300, "广州", "葡萄");
dataset.addValue(400, "北京", "香蕉");
dataset.addValue(400, "上海", "香蕉");
dataset.addValue(400, "广州", "香蕉");
dataset.addValue(500, "北京", "荔枝");
dataset.addValue(500, "上海", "荔枝");
dataset.addValue(500, "广州", "荔枝");
return dataset;
}
}
2：饼状图
PieChartDemo.java饼状图源代码
/**
* 用于演示饼图的生成
*/
public class PieChartDemo {
public static void main(String[] args) throws IOException {
DefaultPieDataset data = getDataSet();
JFreeChart chart = ChartFactory.createPieChart3D("水果产量图", // 图表标题
data, // 数据集
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
);
//中文乱码
PiePlot3D plot = (PiePlot3D) chart.getPlot();
plot.setLabelFont(new Font("黑体", Font.PLAIN, 20));
TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体", Font.PLAIN, 20));
chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
// 写图表对象到文件，参照柱状图生成源码
FileOutputStream fos_jpg = null;
try {
fos_jpg = new FileOutputStream("D:\\Pie3DChart.jpg");
ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f, chart, 400, 300,
null);
} finally {
try {
fos_jpg.close();
} catch (Exception e) {
}
}
}
/**
* 获取一个演示用的简单数据集对象
*
* @return
*/
private static DefaultPieDataset getDataSet() {
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("苹果", 100);
dataset.setValue("梨子", 200);
dataset.setValue("葡萄", 300);
dataset.setValue("香蕉", 400);
dataset.setValue("荔枝", 500);
return dataset;
}
}
其他的图表类型暂时不写了，其实写法也差不多。这里注意两种图形的中文乱码解决方法是不一样的，具体查看源代码中的红色部分
3：将数据库的内容用图形表示出来
index.jsp
<body>
<form action="servlet/ShowChartServlet" method="get" >
<input type="submit" value="jfreechart访问数据库生成图表">
</form>
</body>
showJfreeChart.jsp
<body>
<center>
<img alt="" src="<%=path %>/reports/productSales.jpg">
</center>
</body>
ShowChartServlet.java
public class ShowChartServlet extends HttpServlet {
/**
* 获取一个演示用的组合数据集对象
*
* @return
*/
private static CategoryDataset getDataSet() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
// 从数据库中获取
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver"); // 加载驱动程序
conn = DriverManager
.getConnection(
"jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=utf8",
"root", "root");
ps = conn.prepareStatement("select p.name, count(pcount) from product p join salesitem si on (p.id = si.productid) group by p.id");
rs = ps.executeQuery();
while (rs.next()) {
dataset.addValue(rs.getInt(2), "", rs.getString(1));
}
rs.close();
rs = null;
} catch (SQLException e) {
e.printStackTrace();
}catch (ClassNotFoundException e) {
e.printStackTrace();
}
finally {
if(ps != null){
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
return dataset;
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
CategoryDataset dataset = getDataSet();
JFreeChart chart = ChartFactory.createBarChart3D(
"产品销量图", // 图表标题
"产品", // 目录轴的显示标签
"销量", // 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
);
//中文乱码
CategoryPlot categoryplot = (CategoryPlot) chart.getPlot();
NumberAxis numberaxis = (NumberAxis) categoryplot.getRangeAxis();
CategoryAxis domainAxis = categoryplot.getDomainAxis();
TextTitle textTitle = chart.getTitle();
textTitle.setFont(new Font("黑体", Font.PLAIN, 20));
domainAxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 11));
domainAxis.setLabelFont(new Font("宋体", Font.PLAIN, 12));
numberaxis.setTickLabelFont(new Font("sans-serif", Font.PLAIN, 12));
numberaxis.setLabelFont(new Font("黑体", Font.PLAIN, 12));
chart.getLegend().setItemFont(new Font("宋体", Font.PLAIN, 12));
FileOutputStream fos_jpg = null;
try {
fos_jpg = new FileOutputStream("E:\\Workspaces\\MyEclipse 9\\WebProjects\\JFreeChart\\WebRoot\\reports\\productSales.jpg");
ChartUtilities.writeChartAsJPEG(fos_jpg, 1.0f,chart,400,300,null);
String path = this.getServletContext().getContextPath();
System.out.println(path+"mmmmmmmmmmm");
this.getServletContext().getRequestDispatcher("/showJfreeChart.jsp").forward(request, response);
} finally {
try {
fos_jpg.close();
} catch (Exception e) {}
}
}
}