使用JFreeChart来创建基于web的带交互功能的PIE图表(二)

下面是一个通用的饼图生成sevlet
用法是<IMG alt="Pie chart of summary by reason" useMap=#svcGroupCodeMap border=0
src="pieChart?width=760&height=200&formName=eRAMMISummaryReasonCodeForm&property=result&field1=reasonCode&field2=totalCharge&elemCount=5&numFlag=$&showPercent=true&mapName=svcGroupCodeMap&linkBase=mmiSummaryByReason.do&linkParaKey=svcGroupCode" />
pieChart在session内存中生成了一个图形的MAP对象，如果要使用则应放在最后面并有一段延时：
<%
try{
out.flush();
java.lang.Thread.sleep(1000);
}
catch (Exception delayEx){

}
%>
<logic:notEmpty name="svcGroupCodeMap" scope="session">
<bean:write name="svcGroupCodeMap" scope="session" filter="false"/>
</logic:notEmpty>

下面的这个这个通用的饼图sevlet的代码,基本思路是利用Session中的一些数据生成饼图,formName一般是struts中的一个form, property是这个form中的一个List对象它保存有一系列饼图需要的数据,field1,field2指的是List元素中的两个属性用来提取饼图需求的数据,其它的参数可有可无,不重要, mapName表示需求生成img的MAP图 .
package com.medi.TO.TOOL;
import java.io.*;
import java.lang.reflect.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import org.jfree.chart.*;
import org.jfree.chart.labels.*;
import org.jfree.chart.plot.*;
import org.jfree.data.*;
import org.jfree.chart.urls.StandardPieURLGenerator;
/**
* Title:
* Description: send a PIE chart to brower show the data from session of request refer to
* Copyright: Copyright (c) 2004
* Company: medi.com
* @author Xuxi.Chen
* @version 1.0
*/
public class PieChartServlet extends HttpServlet {
private static final String CONTENT_TYPE = "image/png";
//Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
execute(request, response);
}
//Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
execute(request, response);
}
public void execute(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
try {
String title = request.getParameter("title");
String formName = request.getParameter("formName");
boolean bLegend = true;
if (request.getParameter("legend") != null && request.getParameter("legend").equals("false")) {
bLegend = false;
}
boolean bShowLabel = true;
if (request.getParameter("showLabel") != null && request.getParameter("showLabel").equals("false")) {
bShowLabel = false;
}
int iLegDire = 3;
if (request.getParameter("legDire") != null) {
try {
iLegDire = Integer.parseInt(request.getParameter("legDire"));
} catch (NumberFormatException ex2) {
}
}
boolean bShowPercent = false;
if (request.getParameter("showPercent") != null && request.getParameter("showPercent").equals("true")) {
bShowPercent = true;
}
int iLabelHeight = 10;
if (request.getParameter("labelHeight") != null) {
try {
iLabelHeight = Integer.parseInt(request.getParameter("labelHeight"));
} catch (NumberFormatException ex2) {
}
}
int elemCount = 100;
if (request.getParameter("elemCount") != null) {
try {
elemCount = Integer.parseInt(request.getParameter("elemCount"));
} catch (NumberFormatException ex3) {
}
}
HttpSession session = request.getSession();
Object formInSession = session.getAttribute(formName);
String propName = request.getParameter("property");
String methodName1 = getGetMethodName(request.getParameter("field1"));
String methodName2 = getGetMethodName(request.getParameter("field2"));
Method m = formInSession.getClass().getMethod(getGetMethodName(propName),
new Class[0]);
Collection coll = (Collection) m.invoke(formInSession, null);
DefaultPieDataset data = getDataSet(coll, methodName1, methodName2, elemCount);
JFreeChart chart = ChartFactory.createPieChart3D(title,
data,
bLegend,
false,
false
);
int width = 400;
int height = 300;
try {
width = Integer.parseInt(request.getParameter("width"));
height = Integer.parseInt(request.getParameter("height"));
} catch (NumberFormatException ex) {
}
PiePlot pie = (PiePlot) chart.getPlot();
//pie.setSectionLabelType(PiePlot.NAME_AND_PERCENT_LABELS);
//pie.setSectionLabelType(PiePlot.VALUE_AND_PERCENT_LABELS);
pie.setInteriorGap(0.15);
if (!bShowLabel) {
pie.setLabelGenerator(null);
}
String numFlag = "";
if (request.getParameter("numFlag") != null) {
numFlag = request.getParameter("numFlag");
}
if (bShowPercent) {
pie.setLabelGenerator(new StandardPieItemLabelGenerator(
"{0}=" + numFlag + "{1}({2})", NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance()
));
} else {
pie.setLabelGenerator(new StandardPieItemLabelGenerator(
"{0}=" + numFlag + "{1}", NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance()
));
}
pie.setInteriorGap(0.23);
pie.setLabelFont(new Font("dialog", Font.TRUETYPE_FONT, iLabelHeight));
pie.setMaximumLabelWidth(0.3);
//pie.setLabelGap(0.0);
chart.getLegend().setAnchor(iLegDire);
chart.setBackgroundPaint(java.awt.Color.white);
if (request.getParameter("fieldColor") != null) {
String colorMethodName = getGetMethodName(request.getParameter("fieldColor"));
setPieSecColor(coll, pie, colorMethodName);
}
String mapName = request.getParameter("mapName");
ChartRenderingInfo info = null;
if(mapName != null && mapName.length() > 0){
info = new ChartRenderingInfo();
String linkBase = request.getParameter("linkBase");
String linkParaKey = request.getParameter("linkParaKey"); // would like "svcCodeGroup"
pie.setURLGenerator(new StandardPieURLGenerator(linkBase,linkParaKey));
}
//response.setDateHeader("Expires", System.currentTimeMillis());
//response.setHeader("Cache-Control", "no-cache"); //HTTP 1.1
response.reset();
response.setHeader("Cache-Control", "no-store"); //HTTP 1.1
response.setHeader("Pragma", "no-cache"); //HTTP 1.0
response.setDateHeader("Expires", 0); //prevents caching at the proxy server
response.setContentType(CONTENT_TYPE);
ChartUtilities.writeChartAsPNG(response.getOutputStream(),
chart, width, height, info);
if(info != null){
StringWriter strWriter = new java.io.StringWriter();
PrintWriter w = new java.io.PrintWriter(strWriter);
ChartUtilities.writeImageMap(w, mapName, info);
w.close();
strWriter.close();
request.getSession().setAttribute(mapName, strWriter.getBuffer());
}
}
catch (java.net.SocketException ex1){
}
catch (Exception ex1) {
ex1.printStackTrace(System.out);
}
}
private void setPieSecColor(Collection coll, PiePlot pie, String colorMethodName) {
try {
Iterator iter = coll.iterator();
int iRow = 0;
while (iter.hasNext()) {
Object item = (Object) iter.next();
Method m1 = item.getClass().getMethod(colorMethodName, new Class[0]);
Color clr = (Color) m1.invoke(item, null);
pie.setSectionPaint(iRow, clr);
iRow++;
}
} catch (Exception ex2) {
ex2.printStackTrace();
}
}
private String getGetMethodName(String name) {
StringBuffer strBuf = new StringBuffer("get");
strBuf.append(name);
char ch0 = name.charAt(0);
ch0 = java.lang.Character.toUpperCase(ch0);
strBuf.setCharAt(3, ch0);
return strBuf.toString();
}
private static DefaultPieDataset getDataSet(Collection coll, String methodName1, String methodName2, int elemCount) throws
Exception {
DefaultPieDataset dataset = new DefaultPieDataset();
int iCount = 0;
Iterator iter = coll.iterator();
while (iter.hasNext()) {
if (iCount >= elemCount) {
break;
}
Object item = (Object) iter.next();
Method m1 = item.getClass().getMethod(methodName1, new Class[0]);
java.lang.Comparable data1 = (Comparable) m1.invoke(item, null);
if (data1 == null) {
data1 = "";
}
Method m2 = item.getClass().getMethod(methodName2, new Class[0]);
Number data2 = (Number) m2.invoke(item, null);
//dataset.setValue(data1.toString().trim(), data2);
//System.out.println("data1="+data1+" data2="+data2);
double data = data2.doubleValue();
if(data < 0){
data *= -1.0;
}
dataset.setValue(data1.toString().trim(), data);
iCount++;
}
return dataset;
}
}