怎么从数据库取数据，用JFREECHART显示在JSP页面，定时刷新？

[peiqu123]

如题。。。。。。。希望大虾给个思路或代码。。谢谢

[andy0618]

用AJAX取生成图表的页面，然后显示出来
定时执行AJAX函数

[sunwei_07]

1.怎么从数据库取数据……
不知道怎么回答了～～我也不知道你啥库啥表要啥字段。无非链接，获取，释放
2.Jfreechart 显示

public class Jfree {

private static final String TimeSeries = null;

public static void main(String[] args) {
// create a default chart based on some sample data...
//曲线图标题
String title = "趋势分析";
//曲线图X轴提示
String domain = "月份走势";
//曲线图Y轴提示
String range = "应收余额";
//曲线图自标题
String subtitleStr = "2007财年分析";

Jfree tf = new Jfree();
Vector vc = new Vector();
vc.add("sw");
vc.add("cly");
TimeSeriesCollection dataset = tf.create(vc);
//时间曲线元素
JFreeChart chart = ChartFactory.createTimeSeriesChart(title, domain,
range, dataset, true, true, false);
// then customise it a little...
TextTitle subtitle = new TextTitle(subtitleStr, new Font("黑体",
Font.BOLD, 12));
chart.addSubtitle(subtitle);
chart.setTitle(new TextTitle(title, new Font("隶书", Font.ITALIC, 15)));
//pie.setSeriesLabelFont(new Font("黑体", Font.BOLD, 15));
chart.setBackgroundPaint(new GradientPaint(0, 0, Color.white, 0, 1000,
Color.blue));
//sysout
//输出文件到指定目录

String fileName = "d:\\1.jpeg";
//Coding cod = new Coding();
//fileName = "D:\\jfree\\"+cod.change(fileName);

try {
//for
//System.out.println();
ChartUtilities.saveChartAsJPEG(new File(fileName), 1, chart, 600,
600);
// log.info("....Create image File:" + fileName);
} catch (IOException exz) {
System.out.print("....Cant't Create image File");
}
}

public TimeSeriesCollection create(Vector vc){

TimeSeriesCollection dataset = new TimeSeriesCollection();

TimeSeries[] ob = null;
for (int j = 0; j < vc.size(); j++) {
ob[j] = new TimeSeries((String)vc.get(j));
for (int i = 1991; i < 2008; i++) {
for (int mon = 0; mon < 12; mon++) {
//ibm.add(new Month(mon+1,i),new Double(400-Math.random()*100));
((TimeSeries) ob[j]).add(new TimeSeriesDataItem(new Day(1, mon + 1, i),
new Double(500 + Math.random() * 100)));
}
}
dataset.addSeries((TimeSeries) ob[j]);

}

return dataset;
}
}

[sunwei_07]

3.定时更新

本段代码是用javascript实现页面定时刷新的功能,具体内容如下：
<script>
<!--
var limit="0:10"
if (document.images){
var parselimit=limit.split(":")
parselimit=parselimit[0]*60+parselimit[1]*1
}
function beginrefresh(){
if (!document.images)
return
if (parselimit==1)
window.location.reload()
else{
parselimit-=1
curmin=Math.floor(parselimit/60)
cursec=parselimit%60
if (curmin!=0)
curtime=curmin+" min "+cursec+" sec "
else
curtime=cursec+" sec "
window.status=curtime
setTimeout("beginrefresh()",1000)
}
}
window.onload=beginrefresh
//-->
</script>

加到body中间，这里是0:10为10秒钟，可以自定义

[peiqu123]

不知道能不能用线程做？对JS真是不熟悉。。。
而且显示JFREECHART是在网页中显示的。。。