JfreeChart连接数据库数据显示柱状图

首先编写web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
  
  <servlet>
           <servlet-name>DisplayChart</servlet-name>
           <servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>
 </servlet>
 <servlet-mapping>
           <servlet-name>DisplayChart</servlet-name>
           <url-pattern>/DisplayChart</url-pattern>
 </servlet-mapping>
  
  
  
  
  
</web-app>

 

显示柱状图代码页：index.jsp:

<%@ page contentType="text/html;charset=