ReportUtils.java

package pt.ist.expenditureTrackingSystem.util;

import java.io.ByteArrayOutputStream;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.ResourceBundle;
import java.util.concurrent.ConcurrentHashMap;

import javax.print.PrintService;
import javax.print.attribute.PrintRequestAttributeSet;

import net.sf.jasperreports.engine.JRAbstractExporter;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRExporterParameter;
import net.sf.jasperreports.engine.JRParameter;
import net.sf.jasperreports.engine.JasperExportManager;
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.JRPrintServiceExporterParameter;
import net.sf.jasperreports.engine.util.JRLoader;

import org.apache.commons.lang.StringUtils;

import pt.utl.ist.fenix.tools.util.PropertiesManager;

public class ReportUtils extends PropertiesManager {

    static final private Map<String, JasperReport> reportsMap = new ConcurrentHashMap<String, JasperReport>();

    static public boolean exportToPdfFile(String key, Map parameters, ResourceBundle bundle, Collection dataSource,
            String destination) {
        try {
            final JasperPrint jasperPrint = createJasperPrint(key, parameters, bundle, dataSource);
            if (jasperPrint != null) {
                JasperExportManager.exportReportToPdfFile(jasperPrint, destination);
                return true;
            } else {
                return false;
            }
        } catch (JRException e) {
            return false;
        }
    }

    static public byte[] exportToPdfFileAsByteArray(final String key, final Map parameters, final ResourceBundle bundle,
            final Collection dataSource) throws JRException {
        final JasperPrint jasperPrint = createJasperPrint(key, parameters, bundle, dataSource);

        if (jasperPrint != null) {
            final ByteArrayOutputStream baos = new ByteArrayOutputStream();
            export(new JRPdfExporter(), Collections.singletonList(jasperPrint), baos, (PrintService) null,
                    (PrintRequestAttributeSet) null);
            return baos.toByteArray();
        }

        return null;
    }

    static private JasperPrint createJasperPrint(final String key, final Map parameters, final ResourceBundle bundle,
            Collection dataSource) throws JRException {
        JasperReport report = reportsMap.get(key);

        if (report == null) {
            report = (JasperReport) JRLoader.loadObject(ReportUtils.class.getResourceAsStream(key));
            reportsMap.put(key, report);
        }

        if (report != null) {
            if (parameters != null && bundle != null) {
                parameters.put(JRParameter.REPORT_RESOURCE_BUNDLE, bundle);
            }

            if (dataSource == null || dataSource.isEmpty()) {
                // dummy, engine seems to work not very well with empty data
                // sources
                dataSource = Collections.singletonList(StringUtils.EMPTY);
            }

            return JasperFillManager.fillReport(report, parameters, new TransactionalDataSource(dataSource));
        }

        return null;
    }

    static private void export(final JRAbstractExporter exporter, final List<JasperPrint> prints,
            final ByteArrayOutputStream stream, final PrintService printService,
            final PrintRequestAttributeSet printRequestAttributeSet) throws JRException {

        if (prints.size() == 1) {
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, prints.iterator().next());
        } else {
            exporter.setParameter(JRExporterParameter.JASPER_PRINT_LIST, prints);
        }

        if (stream != null) {
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, stream);
        }

        if (printService != null) {
            exporter.setParameter(JRPrintServiceExporterParameter.PRINT_SERVICE, printService);
        }

        if (printRequestAttributeSet != null) {
            exporter.setParameter(JRPrintServiceExporterParameter.PRINT_REQUEST_ATTRIBUTE_SET, printRequestAttributeSet);
        }

        exporter.exportReport();
        return;
    }

}