关于jfreechart显示图片的问题

herofour444 2011-04-14 01:14:39

rt 最近在做一个管理系统要求能产生柱状图要求从severlet输出
然后就在网上找了一些资料这是我做的
下载包什么的都做好了然后之前做了一个直接从jsp输出的测试成功了现在要求从severlet输出
1.首先配置了web.xml文件增加了如下东西：（不知道这个在从severlet输出有什么用暂时加上了）

<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>
2.下面的是后台代码
public class jfreechart_2103 extends HttpServlet {

public jfreechart_2103() {
super();
}

public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("99999999999999999999999999999999999999");
response.setContentType("image/jpeg");

CategoryDataset dataset = getDataSet2();
JFreeChart chart = ChartFactory.createBarChart3D(
"水果产量图", // 图表标题
"水果", // 目录轴的显示标签
"产量", // 数值轴的显示标签
dataset, // 数据集
PlotOrientation.VERTICAL, // 图表方向：水平、垂直
true, // 是否显示图例(对于简单的柱状图必须是false)
false, // 是否生成工具
false // 是否生成URL链接
);

ChartUtilities.writeChartAsJPEG(response.getOutputStream(),
100,chart,400,300,null);
}
/** * 获取一个演示用的组合数据集对象 * @return */
private static CategoryDataset getDataSet2() {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.addValue(500, "北京", "苹果");
dataset.addValue(100, "上海", "苹果");
dataset.addValue(100, "广州", "苹果");
dataset.addValue(200, "北京", "梨子");
dataset.addValue(200, "上海", "梨子");
dataset.addValue(200, "广州", "梨子");
dataset.addValue(300, "北京", "葡萄");
dataset.addValue(300, "上海", "葡萄");
dataset.addValue(300, "广州", "葡萄");
dataset.addValue(400, "北京", "香蕉");
dataset.addValue(400, "上海", "香蕉");
dataset.addValue(400, "广州", "香蕉");
dataset.addValue(500, "北京", "荔枝");
dataset.addValue(500, "上海", "荔枝");
dataset.addValue(500, "广州", "荔枝");
dataset.addValue(320, "山东", "蔬菜");
return dataset;
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("99999999999991231231231299");
doGet(request,response);
}

public void init() throws ServletException {
// Put your code here
System.out.println("999999999999999999999222222222222222222299999999999999999");
}

}
3.前台是
<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

</head>

<body>
This is my JSP page. <br>
<img src="./jfreechart_2103"/>
</body>
</html>
结果显示的图片是叉叉大侠们帮忙解决下没想法的捧个人场

...全文