Jasper Report generation

Question

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.HashMap;
import java.util.Map;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperRunManager;
public class Reporter {
     public void generateReport() {
          System.out.println("Report Method");
          Map parameters = new HashMap();
          parameters.put("where", "");
          FileOutputStream fos = null;
          Connection c = null;
          try {
               System.out.println("Getting Conncetion");
               Class.forName("oracle.jdbc.driver.OracleDriver");
               c = DriverManager.getConnection(
                         "jdbc:oracle:thin:@10.237.51.5:1521:hrtfddev",
                         "PORTAL_TEST", "PORTAL_TEST");
               System.out.println("Got Connection");
          } catch (ClassNotFoundException e1) {
                         e1.printStackTrace();
          } catch (Exception e) {
               System.out.println("Exception=====");
          try {
               System.out.println("1");
                                   InputStream in = this.getClass().getClassLoader()
                         .getResourceAsStream("newown.jasper");
               System.out.println("3");
               System.out.println("inputstream     " + in);
               System.out.println("expoted report to PDF");
                              byte b[] = JasperRunManager.runReportToPdf(in, parameters, c);
               System.out.println("file output stream started");
               fos = new FileOutputStream("D:/report.pdf");
               System.out.println("the file output stream is " + fos);
               fos.write(b);
               fos.close();
          } catch (FileNotFoundException e) {
               // TODO Auto-generated catch block
               System.out.println("FILE NOT FOUND");
               e.printStackTrace();
          } catch (IOException e) {
               // TODO: handle exception
               System.out.println("IOException");
          } catch (JRException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
               System.out.println("large JRException");
am new to jasper...
problem with this code.. no compilation error nor runtime time error..
It generated a .pdf file but that file is empty... can any one help me out..
Expecting ur replies guys

Answer 1

does this work when you're NOT trying to do it from code? IE: have you used a jasper tool to try this? iReport is free, and there are others that have free trials. They allow you to define the connection parameters and preview the report in the UI. If the PDF comes out with NOTHING, i have to wonder if your query is returning anything. Is there static text in the report? A title? if not, make some static text and see if that is coming out. if it is, your problem seems like the query. IF it's not, I'm not sure :)