jasperReports webapp sample

Mirar los ejemplos del jasperreports-3.1.3-project. En especial hay uno llamado webapp con un servlet que nos viene genial.

package servlets;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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.JasperReport;
import net.sf.jasperreports.engine.export.JRHtmlExporter;
import net.sf.jasperreports.engine.export.JRHtmlExporterParameter;
import net.sf.jasperreports.engine.util.JRLoader;
import net.sf.jasperreports.j2ee.servlets.ImageServlet;
import datasource.WebappDataSource;


/**
* @author Teodor Danciu (teodord@users.sourceforge.net)
* @version $Id: HtmlServlet.java 1236 2006-04-22 07:51:44Z teodord $
*/
public class HtmlServlet extends HttpServlet
{


/**
*
*/
public void service(
HttpServletRequest request,
HttpServletResponse response
) throws IOException, ServletException
{
ServletContext context = this.getServletConfig().getServletContext();

response.setContentType("text/html");
PrintWriter out = response.getWriter();

try
{
File reportFile = new File(context.getRealPath("/reports/WebappReport.jasper"));
if (!reportFile.exists())
throw new JRRuntimeException("File WebappReport.jasper not found. The report design must be compiled first.");

JasperReport jasperReport = (JasperReport)JRLoader.loadObject(reportFile.getPath());

Map parameters = new HashMap();
parameters.put("ReportTitle", "Address Report");
parameters.put("BaseDir", reportFile.getParentFile());

JasperPrint jasperPrint =
JasperFillManager.fillReport(
jasperReport,
parameters,
new WebappDataSource()
);

JRHtmlExporter exporter = new JRHtmlExporter();

request.getSession().setAttribute(ImageServlet.DEFAULT_JASPER_PRINT_SESSION_ATTRIBUTE, jasperPrint);

exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
exporter.setParameter(JRExporterParameter.OUTPUT_WRITER, out);
exporter.setParameter(JRHtmlExporterParameter.IMAGES_URI, "image?image=");

exporter.exportReport();
}
catch (JRException e)
{
out.println("");
out.println("");
out.println("");
out.println("");
out.println("");

out.println("");

out.println("JasperReports encountered this error :");
out.println("

");

e.printStackTrace(out);

out.println("

");

out.println("");
out.println("");
}
}


}