Forward Request giving java.lang.IllegalStateException

Question

Hi Friends,
I am using RequestDispatcher to forwrd my request from one servlet to another
Here's the code
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class TryServlet extends HttpServlet
public void service(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException
try
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String url="jdbc:odbc:con";
Connection con= DriverManager.getConnection(url,"scott","tiger");     
Statement stmt=con.createStatement();
ResultSet rst=stmt.executeQuery("select * from Projects");
response.setContentType("text/html");
PrintWriter out=response.getWriter();
while (rst.next())
String firstname=rst.getString("PIN");
String lastname=rst.getString("ProjectTitle");
out.println("<p> Name:"+firstname+" "+lastname+"");     
con.close();
RequestDispatcher rd=getServletContext().getNamedDispatcher("HelloServlet");
rd.forward(request,response);
return;
catch(Exception e)
e.printStackTrace();
I m getting the error
java.lang.IllegalStateException: Cannot forward after response has been committed
i need to include the two rows of tables before i forwad the request to HelloServlet
What needs to be done?
thanx
Pooja

Answer 1

Don't spread the generation of output over several servlets. Your first servlet should retrieve the data and your second servlet should display the data.
Store the data retrieved as a request attribute before forwarding:
// Data.java
public class Data  {
  public String _firstname;
  public String _lastname;
  public data(String firstname, String lastname)  {
    _firstname = firstname;
    _lastname = lastname;
    return;
//  TryServlet.java
public class TryServlet extends HttpServlet
  List list = new ArrayList();
  while (rst.next())  {  //  store data in list
    String firstname=rst.getString("PIN");
    String lastname=rst.getString("ProjectTitle");
    Data data = new data(firstname, lastname);
    list.add(data);
  con.close();
  request.setAttribute("list", list);  //  store list in request
  RequestDispatcher rd=getServletContext().getNamedDispatcher("HelloServlet");
  rd.forward(request,response);  // list is forwarded as well
  return;
}In HelloServlet, you get the request's attribute and display the data:
  List list = (List)request.getAttribute("list");  //  retrieve list from request
  Iterator it = list.iterator();
  while (it.hasNext())  {  //  retrieve data from list and display
    Data data = (Data)it.next();
    out.println("<p>Name: " + data._firstname + " " + data._lastname + "</p>");
  }Btw, for displaying the data, a JSP will do better.
Two Bears.