<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 1.0//EN" 

"http://www.opensymphony.com/xwork/xwork-1.0.dtd">
<xwork>
    <include file="webwork-default.xml"/>   
   <package name="default" extends="webwork-default">
    ...
    </package>
</xwork>

<result-types>
   <result-type name="chart" class="pawpaw.test.ChartResult"/>
   </result-types>

<action name="viewModerationChart" class="pawpaw.test.ViewModerationChartAction"> 
  <result name="success" type="chart"> 
    <param name="width">400</param>
    <param name="height">300</param> </result>
</action>

<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>/servletDisplayChart</url-pattern>
    </servlet-mapping>

package pawpaw.test;

import com.opensymphony.webwork.ServletActionContext;
import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.Result;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import java.io.OutputStream;
import javax.servlet.http.HttpServletResponse;
/*
 * <p>Description: 把chart文件流换成是通过HttpServletResponse
 *    对象获取到的输出流在浏览器中输出</p>
 * author: pawpaw
 * @version 1.0  12/15/2003
 */
public class ChartResult implements Result {
    JFreeChart chart;
    boolean chartSet = false;
    private int height;
    private int width;

    public void setChart(JFreeChart chart) {
        this.chart = chart;
        chartSet = true;
    }
    //设置图片的长度
    public void setHeight(int height) {
        this.height = height;
    }
    //设置图片的宽度
    public void setWidth(int width) {
        this.width = width;
    }

    public void execute(ActionInvocation invocation) throws Exception {
        JFreeChart chart = null;

        if (chartSet) {
            chart = this.chart;
        } else {
            chart = (JFreeChart) invocation.getStack().findValue("chart");
        }

        if (chart == null) {
            throw new NullPointerException("No chart found");
        }
        
        //把文件流换成是通过HttpServletResponse对象获取到的输出流
        HttpServletResponse response = ServletActionContext.getResponse();
        OutputStream os = response.getOutputStream();
        ChartUtilities.writeChartAsPNG(os, chart, width, height);
        os.flush();
    }
}

package pawpaw.test;

import java.awt.Insets;
import java.awt.Font;
import java.io.PrintWriter;
import javax.servlet.http.HttpSession;
import org.jfree.data.*;
import org.jfree.chart.*;
import org.jfree.chart.plot.*;
import org.jfree.chart.entity.*;
import org.jfree.chart.urls.*;
import org.jfree.chart.servlet.*;
import org.jfree.chart.labels.StandardPieToolTipGenerator;
import org.jfree.util.Rotation;
import com.opensymphony.xwork.ActionSupport;
/*
 *<p>Description: 输出一条斜线chart</p>
 * author: pawpaw
 * @version 1.0  12/15/2003
 */
public class ViewModerationChartAction extends ActionSupport {   
   private JFreeChart chart;
   public String execute() throws Exception {
      // 创建chart文件数据集
      XYSeries dataSeries = new XYSeries(null);
      for (int i = 0; i <= 100; i++) {
         dataSeries.add(i, RandomUtils.nextInt());
      }
      XYSeriesCollection xyDataset = new XYSeriesCollection(dataSeries);
            ValueAxis xAxis = new NumberAxis("Raw Marks");//x轴坐标
      ValueAxis yAxis = new NumberAxis("Moderated Marks");//y轴坐标     
      // 设置chart的样式
      chart =new JFreeChart(
            "Moderation Function",// 图表标题
            JFreeChart.DEFAULT_TITLE_FONT,
            new XYPlot(
               xyDataset,
               xAxis,
               yAxis,
               new                         
           StandardXYItemRenderer(StandardXYItemRenderer.LINES)),// 数据集
            false    //是否生成URL链接
            );
      chart.setBackgroundPaint(java.awt.Color.white);  //设置图片的背景色
      Font font = new Font("黑体",Font.CENTER_BASELINE,20);//设置图片标题的字体和大小
      TextTitle _title = new TextTitle(title);
      _title.setFont(font);
      chart.setTitle(_title);
      return super.SUCCESS;
   }   
   public JFreeChart getChart() {
      return chart;
   }
}