How to merge multiple reports into a single report in JasperReports

import java.io.FileOutputStream;

import java.util.ArrayList;

import java.util.HashMap;

import net.sf.jasperreports.engine.JREmptyDataSource;

import net.sf.jasperreports.engine.JRExporter;

import net.sf.jasperreports.engine.JRParameter;

import net.sf.jasperreports.engine.JRPrintPage;

import net.sf.jasperreports.engine.JasperFillManager;

import net.sf.jasperreports.engine.JasperPrint;

import net.sf.jasperreports.engine.JasperReport;

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

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

import net.sf.jasperreports.engine.fill.JRFileVirtualizer;

import net.sf.jasperreports.engine.util.JRLoader;

public class JasperReportMerge {

ArrayList reportsList = new ArrayList();

HashMap params = new HashMap();

JasperPrint jrPrint = new JasperPrint();

public void buildReport() throws Exception {

String templateFile = "C://Testing//MergeReportTemplate.jasper";

JasperReport jrReport = (JasperReport) JRLoader.loadObject(templateFile);

JRFileVirtualizer virtualizer = null;

JasperPrint jp = null;

for(int i=0; i<5; i++) {

virtualizer = new JRFileVirtualizer(2, "C://tmp");

virtualizer.setReadOnly(true);

params.put(JRParameter.REPORT_VIRTUALIZER, virtualizer);

// Create dummy data for the each report

params.put("name", "Hello " + i);

params.put("ic", "IC " + i);

params.put("address", i + " Address");

jp = JasperFillManager.fillReport(jrReport, params, new JREmptyDataSource());

reportsList.add(jp); // adding the report into list

// Clean the virtualizer.

// If you didnt clean it, you might encounter error such as

// "The virtualizer is used by more contexts than its in-memory cache size XXX"

virtualizer.cleanup();

}

if (reportsList != null && reportsList.size() > 0) {

jrPrint = mergeReport(); // merge the report

} else {

jrPrint = JasperFillManager.fillReport(jrReport, params, new JREmptyDataSource());

}

exportReport();

}

protected JasperPrint mergeReport() throws Exception {

JasperPrint jrPrint = new JasperPrint();

JasperPrint jp = null;

jp = (JasperPrint) reportsList.get(0);

// set the report layout

jrPrint.setOrientation(jp.getOrientation());

jrPrint.setLocaleCode(jp.getLocaleCode());

jrPrint.setPageHeight(jp.getPageHeight());

jrPrint.setPageWidth(jp.getPageWidth());

jrPrint.setTimeZoneId(jp.getTimeZoneId());

jrPrint.setName(jp.getName());

// get each report and merge it 1 by 1

for(int i=0; i<reportsList.size(); i++) {

jp = (JasperPrint) reportsList.get(i);

ArrayList list = (ArrayList) jp.getPages();

// Merging the reports into 1 single report

for(int j=0; j

jrPrint.addPage((JRPrintPage) list.get(j));

}

}

return jrPrint;

}

protected void exportReport() throws Exception {

FileOutputStream fileOut = new FileOutputStream("C://Testing//MergeReportTemplate.pdf");

JRExporter exporter = new JRPdfExporter();

exporter.setParameter(JRPdfExporterParameter.FORCE_LINEBREAK_POLICY, Boolean.TRUE);

exporter.setParameter(JRPdfExporterParameter.OUTPUT_STREAM, fileOut);

exporter.setParameter(JRPdfExporterParameter.JASPER_PRINT, jrPrint);

System.out.println("Exporting...");

exporter.exportReport();

fileOut.flush();

fileOut.close();

}

public static void main(String[] args) throws Exception {

JasperReportMerge jem = new JasperReportMerge();

jem.buildReport();

System.out.println("Done");

}

}