其次配置web.xml调用的现成的显示类
< 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 > /servlet/DisplayChart </ url-pattern >
</ servlet-mapping >
柱状图类的详细实例