本文实例讲述了JavaWeb实现图形报表折线图的方法。分享给大家供大家参考，具体如下：
步骤说明:
1. 导入log4j.jar,jfreechart-0.9.18.jar,jdom.jar,jcommon-0.9.3.jar四个jar包
2. 在某个包中写入Tuxin.Java类
package com.mengya.util;
import java.awt.Color;
import java.awt.Font;
import java.io.PrintWriter;
import javax.servlet.http.HttpSession;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardLegend;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.LineAndShapeRenderer;
import org.jfree.chart.servlet.ServletUtilities;
import org.jfree.data.DefaultCategoryDataset;
public class Line{
private DefaultCategoryDataset dataset = new DefaultCategoryDataset();
public void setValue(int sum, String line, String wfield) {
dataset.addValue(sum, line, wfield);
}
public String generateLineChart(String title,String wfield, String hfield, HttpSession session, PrintWriter pw,int wPhoto,int hPhoto) {
String filename = null;
try {
final JFreeChart chart = ChartFactory.createLineChart ( title, // 图表标题 wfield, // 横轴的显示标签 hfield, // 纵轴的显示标签 dataset, //数据集 PlotOrientation.VERTICAL, // 图表方向：水平、垂直 true, // 是否显示图例 true, // 是否生成提示工具 tooltips false // 是否生成URL链接 );
StandardLegend legend = (StandardLegend) chart.getLegend();
//生成图例 legend.setDisplaySeriesShapes(true);
//显示图例形状 legend.setShapeScaleX(1.5);
//设置图例X轴的大小 legend.setShapeScaleY(1.5);
//设置图例Y轴的大小 legend.setDisplaySeriesLines(true);
//显示图示项的横线 //设置图片的背景色 chart.setBackgroundPaint(new java.awt.Color(189,235,255));
CategoryPlot plot = (CategoryPlot) chart.getPlot();
plot.setBackgroundPaint(new Color(239,251,255));
//生成图片中墙体的背景色 plot.setRangeGridlinePaint(Color.black);
//生成图片中格子线的颜色 // 没有数据时显示的消息 plot.setNoDataMessage("没有相关统计数据");
plot.setNoDataMessageFont(new Font("黑体", Font.CENTER_BASELINE, 16));
plot.setNoDataMessagePaint(Color.RED);
NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
//设置图中的刻度线的单位 rangeAxis.setAutoRangeIncludesZero(true);
//强制在自动选择的数据范围中包含0 LineAndShapeRenderer renderer = (LineAndShapeRenderer) plot.getRenderer();
renderer.setDrawShapes(true);
//折线的数据点根据分类使用不同的形状 renderer.setItemLabelsVisible(true);
//显示每个点上的数据值的提示工具,数据标签是否可见 ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
//500是图片长度，300是图片高度 filename = ServletUtilities.saveChartAsPNG(chart, wPhoto, hPhoto, info, session);
ChartUtilities.writeImageMap(pw, filename, info);
pw.flush();
}
catch(Exception e) {
e.printStackTrace();
}
return filename;
}
}
3. 配置web.xml,在web.xml中添加如下内空:
<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>
4. 在要显示图片的jsp中添加内容:
<%@ page language="java" import="java.util.*,com.mengya.util.Line,com.mengya.bean.StuBean" pageEncoding="gbk"%><%@page import="java.io.PrintWriter;
"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>折线图</title> </head> <body> <% Line tt = new Line();
//第一条折线 List ar = (ArrayList) request.getAttribute("arr1");
for (int i = 0;
i < ar.size();
i++) {
StuBean bean = (StuBean) ar.get(i);
tt.setValue((int) bean.getS_money(), "张明学个人消费比例图", bean.getS_month()+ "");
}
//条二条折线 ar = (ArrayList) request.getAttribute("arr2");
for (int i = 0;
i < ar.size();
i++) {
StuBean bean = (StuBean) ar.get(i);
tt.setValue((int) bean.getS_money(), "梦娅个人消费比例图", bean.getS_month()+ "");
}
//说明:tt.setValue(int a,String b,String c) //其中的第二个参数b是该条折线的名字,每条折线的名字最好不要一样. String filename = tt.generateLineChart("个人消费比例图", "月 份", "费 用", session, new PrintWriter(out), 800, 550);
String graphURL = request.getContextPath() + "/DisplayChart?filename=" + filename;
%> <P ALIGN="CENTER"> <img src="<%=graphURL %>" width=800 height=550 border=1 usemap="#<%=filename%>"> </body></html>
希望本文所述对大家JSP程序设计有所帮助。
