Struts2+JFreeChart-阿里云开发者社区

下面以边帖图片和代码的方式来讲解Struts2与JFreeChart的整合。
搭建环境：首先帖一张工程的目录结构以及所需的jar包。注意:如果你不打算自己写ChartResult的话只需要引入 struts2-jfreechart-plugin-2.0.6.jar(这个在struts-2.0.6-all.zip可以找到了):

1.依次帖web.xml、struts.xml、struts.properties和struts-jfreechart.xml几个配置文件的代码：
web.xml

<? xml version="1.0" encoding="UTF-8" ?>
< web-app version ="2.4"
    xmlns ="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation ="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" >

     < filter >
         < filter-name > struts2 </ filter-name >
         < filter-class >
            org.apache.struts2.dispatcher.FilterDispatcher
         </ filter-class >
     </ filter >
     < filter-mapping >
         < filter-name > struts2 </ filter-name >
         < url-pattern > /* </ url-pattern >
     </ filter-mapping >
</ web-app >

struts.xml

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd" >

< struts >
     < include file ="struts-jfreechart.xml" />
</ struts >

struts.properties

struts.ui.theme = simple

struts-jfreechart.xml

说明：这里只需要说明下struts-jfreechart.xml，这里直接调用已经写好的类ChartResult，这个类是继承自com.opensymphony.xwork2.Result,传入生成图片大小的参数width和height就可以了。
2. 新建 JFreeChartAction 继承 ActionSupport,生成JFreeChart对象并保存到chart中，注意这个名称是固定的。

package com.tangjun.struts2;

import com.opensymphony.xwork2.ActionSupport;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;

public class JFreeChartAction extends ActionSupport {

     /**
     *
      */
     private static final long serialVersionUID = 5752180822913527064L ;

     // 供ChartResult调用->ActionInvocation.getStack().findValue("chart")
     private JFreeChart chart;

    @Override
     public String execute() throws Exception {
         // 设置数据
        DefaultPieDataset data = new DefaultPieDataset();
        data.setValue( " Java " , new Double( 43.2 ));
        data.setValue( " Visual Basic " , new Double( 1.0 ));
        data.setValue( " C/C++ " , new Double( 17.5 ));
        data.setValue( " tangjun " , new Double( 60.0 ));
         // 生成JFreeChart对象
        chart = ChartFactory.createPieChart( " Pie Chart " , data, true , true , false );

         return SUCCESS;
    }

     public JFreeChart getChart() {
         return chart;
    }

     public void setChart(JFreeChart chart) {
         this .chart = chart;
    }
}

OK！至此代码已经全部贴完。
输入访问 http://localhost:8080/Struts2JFreeChart/jfreechart/JFreeChartAction.action
显示结果如下：

补充
以上生成的图片是PNG格式的图片，如果需要自定义图片格式的话（好像只能支持JPG和PNG格式），那么自己写一个ChartResult继承自StrutsResultSupport，见代码：

package com.tangjun.struts2.chartresult;

import java.io.OutputStream;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.StrutsResultSupport;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;

import com.opensymphony.xwork2.ActionInvocation;

public class ChartResult extends StrutsResultSupport {

     /**
     *
      */
     private static final long serialVersionUID = 4199494785336139337L ;

     // 图片宽度
     private int width;
     // 图片高度
     private int height;
     // 图片类型 jpg,png
     private String imageType;


    @Override
     protected void doExecute(String arg0, ActionInvocation invocation) throws Exception {
        JFreeChart chart = (JFreeChart) invocation.getStack().findValue( " chart " );
        HttpServletResponse response = ServletActionContext.getResponse();
        OutputStream os = response.getOutputStream();

         if ( " jpeg " .equalsIgnoreCase(imageType) || " jpg " .equalsIgnoreCase(imageType))
            ChartUtilities.writeChartAsJPEG(os, chart, width, height);
         else if ( " png " .equalsIgnoreCase(imageType))
            ChartUtilities.writeChartAsPNG(os, chart, width, height);
         else
            ChartUtilities.writeChartAsJPEG(os, chart, width, height);

        os.flush();

    }
     public void setHeight( int height) {
         this .height = height;
    }

     public void setWidth( int width) {
         this .width = width;
    }

     public void setImageType(String imageType) {
         this .imageType = imageType;
    }

}

如此的话还需要小小的修改一下struts-jfreechart.xml：

<! DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd" >

< struts >
     < package name ="jFreeChartDemonstration" extends ="struts-default"
        namespace ="/jfreechart" >
         
         < result-types >
             
             < result-type name ="chart" class ="com.tangjun.struts2.chartresult.ChartResult" ></ result-type >
         </ result-types >

         < action name ="JFreeChartAction" class ="com.tangjun.struts2.JFreeChartAction" >
               
               < result type ="chart" >
                    < param name ="width" > 400 </ param >
                    < param name ="height" > 300 </ param >
                    < param name ="imageType" > jpg </ param >
             </ result >
         </ action >
     </ package >
</ struts >

本文转自博客园农民伯伯的博客，原文链接：Struts2+JFreeChart，如需转载请自行联系原博主。

Struts2+JFreeChart

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