Question

我正在尝试根据用户输入生成图表。我在Struts 2框架中使用JFree Charts。在图表生成Action类中，我无法实现ModelDriven概念;我也无法从HttpServletRequest对象中检索参数值。

如果我通过实施ModelDriven或ServletRequestAware调用图表生成操作类，它可以正常工作，但它会在下一页显示图表。我需要根据用户输入生成图表。

我没有成功搜索有关JFree和Struts 2的信息;任何有用的教程链接也将不胜感激。

这是我的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>
<package name="jfree" extends="jfreechart-default">
            <action name="chartAction" class="com.kogent.action.ChartAction">
                <result name="success" type="chart">
                    <param name="width">500</param>
                    <param name="height">300</param> 
                </result>
            </action>
    </package>          
</struts>

这是我的Action类

package com.kogent.action;

import java.util.Random;

import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.StandardXYItemRenderer;

import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;

public class ChartAction extends ActionSupport implements ModelDriven<FormBean>,Preparable{

    private JFreeChart chart;
    private FormBean bean;

    @Override
    public FormBean getModel() {
        // TODO Auto-generated method stub
        return bean;
    }
    @Override
    public void prepare() throws Exception {
        // TODO Auto-generated method stub
        bean=new FormBean();
    }



    public String execute() throws Exception {
        // chart creation logic...
        System.out.print(bean.getCategory()+"    "+bean.getChartType());
        //if remove this above line my action runs fine but i require this vales from the user
        XYSeries dataSeries = new XYSeries(new Integer(1)); 
        for (int i = 0; i <= 100; i++) {

            dataSeries.add(i, new Random().nextInt(50));
        }

        XYSeriesCollection xyDataSet = new XYSeriesCollection(dataSeries);

        ValueAxis xAxis = new NumberAxis("Marks");
        ValueAxis yAxis = new NumberAxis("Age");
        chart =
            new JFreeChart("Chart Title", JFreeChart.DEFAULT_TITLE_FONT,
                new XYPlot(xyDataSet,xAxis, yAxis,
                        new StandardXYItemRenderer(StandardXYItemRenderer.LINES)),
                false);
        chart.setBackgroundPaint(java.awt.Color.white);

        return super.SUCCESS;
    }

    public JFreeChart getChart() {
        return chart;
    }
}

Answer 1

根据这个jfree图表，有很多例子，只是我给这些链接检查出来。

First：实现任何jfree图表除了servlet request aware和servlet response aware之外没有任何其他要求，请求是用于接收用户的请求，响应是用于向用户提供输出。您希望使用'ModelDriven' interface ( it gains the extra ability to transfer the form data into the object automatically)。

只需使用此链接。

Create chart and Display them dynamically in JSP

Create area chart in JSP page using JFreeChart

Creating Pie Charts with JFreeChart

Already discussion are there in stack overflow only

This is official site it will help full for you

无法使用JFree在Struts 2 Action Class中实现ModelDriven或ServletRequestAware

1 个答案: