此处使用了Java BeanCollection作为DataSource。

 

JSP页面代码：

 

<%@ page errorPage="error.jsp" %>

<%@ page 

import="reportDatasource.*" %>

<%@ page 

import="net.sf.jasperreports.engine.*" %>

<%@ page 

import="net.sf.jasperreports.engine.util.*" %>

<%@ page 

import="net.sf.jasperreports.engine.export.*" %>

<%@ page 

import="net.sf.jasperreports.j2ee.servlets.*" %>

<%@ page 

import="java.util.*" %><%@ page 

import="java.io.*" %>

<%@ page 

import="java.net.URLEncoder" %>

<%@ page 

import="javax.servlet.*" %>

<%@page language="java" contentType="application/x-msdownload"    pageEncoding="UTF-8"%>

<%

      String requestFileName = "LineReport";//报表的名称

      String reportFileName = requestFileName +".jasper";

      String fileDownName = "XXX报表";

      Map parameters = 

new HashMap();

     

//

 parameters.put("ReportTitle", "Address Report"); //向报表传递参数   

      JasperPrint jasperPrint = JavaBeanListDataSoureFactory.createJasperPrintByJavaBeanList(reportFileName, parameters, LocationValueBeanFactory.getPageLoadTimeHistoryLineReportBeanCollection());        

    

       

//

输出

       PathClassPath classpath = 

new PathClassPath();

      String stringpath =  application.getRealPath("/reports/"+reportFileName);

     

      System.out.print("reportFileName="+stringpath);

    

      File sourceFile  =

new File(stringpath);

      

long start = System.currentTimeMillis();

    

      System.err.println("PDF creation time : " + (System.currentTimeMillis() - start));

      

//

下载

      response.reset();

//

      response.setContentType("application/x-download");   

      String filedisplay = fileDownName+".pdf";

      filedisplay = URLEncoder.encode(filedisplay,"UTF-8");

      response.addHeader("Content-Disposition","attachment;filename=" + filedisplay);

      OutputStream outp = 

null;

    

      

try

      {

          outp = response.getOutputStream();

      

           JasperExportManager.exportReportToPdfStream(jasperPrint, outp);

           

          outp.flush();

      }

      

catch(Exception e)

      {

          System.out.println("Error!");

          e.printStackTrace();

      }

      

finally

      {

          

if(outp != 

null)

          {

              outp.close();

              outp = 

null;

          }

          

//

如下处理 getOutputStream() has already been called for this response 异常

      

          out.clear();

          out = pageContext.pushBody();

      }

%>

 

 

 其中：

LocationValueBeanFactory.getPageLoadTimeHistoryLineReportBeanCollection() 

为返回一个实体的数组的List：

 Arrays.asList( LocationValueBean [] data); 

 

 其中：

 JavaBeanListDataSoureFactory.createJasperPrintByJavaBeanList ()

代码为：

 //本类可能会用到的包：

 //

import java.io.File;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.List;

import java.util.Map;

import java.util.Properties;

import net.sf.jasperreports.engine.JRException;

import net.sf.jasperreports.engine.JRExporterParameter;

import net.sf.jasperreports.engine.JRRuntimeException;

import net.sf.jasperreports.engine.JasperFillManager;

import net.sf.jasperreports.engine.JasperPrint;

import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;

import net.sf.jasperreports.engine.export.JRHtmlExporter;

import net.sf.jasperreports.engine.export.JRHtmlExporterParameter;

import net.sf.jasperreports.j2ee.servlets.*;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

//

 

 //

       

public 

static JasperPrint  createJasperPrintByJavaBeanList(String reportFileName,Map parameters,Collection collection)

        {

           

            String path = "";

            Properties prop = 

new Properties();

            

try {

                InputStream in = JavaBeanListDataSoureFactory.

class.getClassLoader().getResourceAsStream("report.properties");

                prop.load(in);

                path = prop.getProperty("site.reportjasper.path");

                in.close();

            } 

catch (FileNotFoundException e) {

                e.printStackTrace();

            } 

catch (IOException e) {

                e.printStackTrace();

            }

            JRHtmlExporter exporter = 

new JRHtmlExporter();

            JasperPrint jasperPrint = 

null;

             

//

PathClassPath classpath = new PathClassPath();

            

//

ReadConfigInfo conf = new ReadConfigInfo();

             String reportFileNameResult = path+reportFileName;

            File reportFile = 

new File(reportFileNameResult);

            

if (!reportFile.exists())

                

throw 

new JRRuntimeException("File "+reportFileName+" not found. The report design must be compiled first.");

            parameters.put("ReportTitle", "Address Report");

            parameters.put("BaseDir", reportFile.getParentFile());

            

try {

                

                jasperPrint = 

                    JasperFillManager.fillReport(

                        reportFileNameResult, 

                        parameters, 

                        

new JRBeanCollectionDataSource(collection)

                        );

                

            } 

catch (JRException e) {

                

//

 TODO Auto-generated catch block

                e.printStackTrace();

            }

            

return jasperPrint;

        }

 

 

PS:博客园中的插入代码依然有问题啊，有的时候最上面一行会从代码块中跑出来，有的时候最下面一行会跑出来，我的环境：Win7 x64+Chrome 21.01180.89