Jasper Util 类

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.Writer;
import java.sql.Connection;
import java.util.Map;

import net.sf.jasperreports.engine.JRAbstractExporter;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRExporterParameter;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.export.JExcelApiExporter;
import net.sf.jasperreports.engine.export.JRHtmlExporter;
import net.sf.jasperreports.engine.export.JRHtmlExporterParameter;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.engine.export.JRPdfExporterParameter;
import net.sf.jasperreports.engine.export.JRXlsExporterParameter;
import net.sf.jasperreports.engine.util.JRLoader;

import org.apache.log4j.Logger;

import com.ssc.cba.report.ReportClient;
import com.ssc.cba.service.util.DBUtil;
import com.ssc.faw.util.GenException;

public class JasperReportUtil
{
    private static Logger logger = Logger.getLogger(JasperReportUtil.class);
    
    /**
     * export report
     * 
     * @param jasperPrint
     * @param param
     * @return
     * @throws Exception
     */
    public byte[] exportReport(JasperPrint jasperPrint, Map<String, Object> param) throws Exception
    {
	ByteArrayOutputStream oStream = new ByteArrayOutputStream();
	JRAbstractExporter exporter = fillJasperPrint(jasperPrint, param);
	exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, oStream);
	
	logger.info("[JasperReportUtil - exportReport] Exporting report starting...");
	long startTime = System.currentTimeMillis();
	exporter.exportReport();
	long endTime = System.currentTimeMillis();
	logger.info("[JasperReportUtil - exportReport] Exporting report end. It takes " + (endTime - startTime) + " ms");
	byte[] bytes = oStream.toByteArray();
	return bytes;
    }

    /**
     * fill the data into jasper print object
     * 
     * @param jasperPrint
     * @param param
     * @return
     * @throws Exception
     */
    public static JRAbstractExporter fillJasperPrint(JasperPrint jasperPrint, Map<String, Object> param) throws Exception
    {
	try
	{
	    String mode = (String) param.get(ReportClient.REPORT_TYPE);
	    logger.info("[JasperReportUtil - fillJasperPrint] The type of exported report is " + mode);
	    JRAbstractExporter exporter = getJRExporter(mode);
	    exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
	    return exporter;
	}
	catch (Exception e)
	{
	    logger.error("[JasperReportUtil - fillJasperPrint] Error occurs when filling Jasper report: " + e);
	    throw new GenException(e);
	}
    }

    /**
     * export report
     * 
     * @param param
     * @return
     * @throws GenException
     */
    public byte[] exportReport(Map<String, Object> param) throws GenException
    {
	byte[] bytes = null;
	Connection conn = null;
	try
	{
	    conn = DBUtil.getConnection();
	    JasperPrint jasperPrint = getJasperPrint(param, conn);
	    bytes = exportReport(jasperPrint, param);
	}
	catch (Exception e)
	{
	    logger.error("[JasperReportUtil - exportReport] Error occurs when exporting Jasper report: " + e);
	    throw new GenException(e);
	}
	finally
	{
	    DBUtil.closeConnection(conn);
	}
	return bytes;
    }

    /**
     * retrieve the Jasper exporter
     * 
     * @param docType
     * @return
     */
    public static JRAbstractExporter getJRExporter(String exportType) throws GenException
    {
	JRAbstractExporter exporter = null;

	if (ReportClient.EXPORT_PDF.equalsIgnoreCase(exportType))
	{
	    exporter = new JRPdfExporter();
	    configurePdfExporter(exporter);
	}
	else if (ReportClient.EXPORT_EXCEL.equalsIgnoreCase(exportType))
	{
	    exporter = new JExcelApiExporter();
	    configureXlsExporter(exporter);
	}
	else if (ReportClient.EXPORT_HTML.equalsIgnoreCase(exportType))
	{
	    exporter = new JRHtmlExporter();
	    configureHtmlExporter(exporter);

	}
	else
	{
	    throw new GenException("[JasperReportUtil - getJRExporter] The type of exported Jasper report doesn't exist!");
	}

	return exporter;
    }

    private static void configurePdfExporter(JRAbstractExporter exporter)
    {
	exporter.setParameter(JRPdfExporterParameter.CHARACTER_ENCODING, ReportClient.CHARACTER_ENCODING);
    }

    private static void configureXlsExporter(JRAbstractExporter exporter)
    {
	exporter.setParameter(JRXlsExporterParameter.CHARACTER_ENCODING, ReportClient.CHARACTER_ENCODING);
	exporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS, Boolean.TRUE);
	exporter.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.FALSE);
	exporter.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND, Boolean.FALSE);
    }

    private static void configureHtmlExporter(JRAbstractExporter exporter)
    {
	exporter.setParameter(JRHtmlExporterParameter.IS_USING_IMAGES_TO_ALIGN, Boolean.FALSE);
	exporter.setParameter(JRHtmlExporterParameter.ZOOM_RATIO, Float.parseFloat("1.2"));
	exporter.setParameter(JRHtmlExporterParameter.CHARACTER_ENCODING, ReportClient.CHARACTER_ENCODING);
    }

    /**
     * retrieve the Jasper Print Object
     * 
     * @param param
     * @param conn
     * @return
     * @throws GenException
     */
    public static JasperPrint getJasperPrint(Map<String, Object> param, Connection conn) throws GenException
    {
	JasperPrint jasperPrint = null;
	try
	{
	    String jasperFile = (String) param.get(ReportClient.REPORT_NAME);
	    if (jasperFile == null)
	    {
		throw new GenException("[JasperReportUtil - getJasperPrint] The Jasper report template can't be found out!");
	    }
	    JasperReport jasperReport = (JasperReport) JRLoader.loadObject(new File(jasperFile));
	    jasperPrint = JasperFillManager.fillReport(jasperReport, param, conn);
	}
	catch (JRException e)
	{
	    logger.error("[JasperReportUtil - getJasperPrint] Error occurs when retrieving JasperPrint Object: " + e);
	    throw new GenException(e);
	}
	return jasperPrint;
    }

    /**
     * preview html jasper report
     * 
     * @param param
     * @param writer
     * @throws GenException
     */
    public static void previewHtmlReport(Map<String, Object> param, Writer writer) throws GenException
    {
	Connection conn = null;
	try
	{
	    conn = DBUtil.getConnection();
	    JasperPrint jasperPrint = JasperReportUtil.getJasperPrint(param, conn);
	    JRAbstractExporter exporter = JasperReportUtil.fillJasperPrint(jasperPrint, param);
	    exporter.setParameter(JRHtmlExporterParameter.OUTPUT_WRITER, writer);
	    logger.info("[JasperReportUtil - previewHtmlReport] Preview report starting...");
	    long startTime = System.currentTimeMillis();
	    exporter.exportReport();
	    long endTime = System.currentTimeMillis();
	    logger.info("[JasperReportUtil - previewHtmlReport] Preview report end. It takes " + (endTime - startTime) + " ms");
	}
	catch (Exception e)
	{
	    logger.error("[JasperReportUtil - previewHtmlReport] Error occurs when previewing Html Report: " + e);
	    throw new GenException(e);
	}
	finally
	{
	    DBUtil.closeConnection(conn);
	}
    }
}