JDBC return null when called from a servlet

[ankur tyagi]

i have a class file that does all the jdbc stuff and return the values from the database to the servlet..
but the problem is when i call the class from the servlet , the resultset is null
but when i call the same class from other class' main: the values are returning jsut fine..
i even stuffed all the functions in the servlet class but still no solution
the oracle is running on default 8080 port and tomcat is running on 8081.
here is the servlet with everything in it

   
import javax.servlet.*;
import java.sql.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class AirportSelect1 extends HttpServlet
{
	Statement stmt;
	ResultSet rset;
	PreparedStatement p;
	Connection con;
	public void doPost(HttpServletRequest request,
						HttpServletResponse response)
						throws IOException, ServletException
		{

			String c= request.getParameter("airport");
			String fcode;
			String q="Select * from FlightCD where FromD like 'Delhi'";
			List code= new ArrayList();
			ResultSet rs=View(q);
			try
			{
				while(rs.next())
				{
					fcode=rs.getString(1);
						code.add(fcode);
				}
			response.setContentType("text/html");
			PrintWriter out= response.getWriter();
			out.println("Airports list<br>");
			out.println(code.size());
			Iterator it = code.iterator();
			out.println("Good till now");
			while(it.hasNext())
				{
					out.print("<br> try : " + it.next());
				}
			}
			catch(Exception e)
			{
				response.setContentType("text/html");
			PrintWriter out= response.getWriter();
							out.println("no result set");

				System.out.println(e.toString());
			}
		}
		public Connection conn() throws SQLException
				{

					try
						{
							Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
						}
					catch(ClassNotFoundException e)
						{
							System.out.println("Database Driver not found");
							System.out.println(e.toString());
						}
					catch(Exception e)
						{
							System.out.println(e.toString());
						}
					return(DriverManager.getConnection("jdbc:odbc:link","system","oracle"));
					}
			public  ResultSet View(String qry)
			{
				try
				{
					 con=conn();
					qry=qry;
					stmt=con.createStatement();
					rset=stmt.executeQuery(qry);


				}
				catch(Exception e)
				{
					System.out.println(e.toString());
				}

			return rset;
	}
	}

 

can any one help its important for me.
i am stuck on it....

[Paul Sturrock]

oracle is running on default 8080

That's not the default port for Oracle.

Why are you using the JDBC-ODBC bridge to connect to Oracle? Would it not be easier and better to use the thin driver?

When you say "the resutls set is null" do you mean it is empty or are you getting a NullPointerException?

One other thing - you should close connections after you've finished with them otherwsie you waste database resources.

[ankur tyagi]

i am getting null pointer exception so the catch is running ..
my oracle is running on 8080 because it clashed with Tomcat so i changed the port for tomcat from 8080 to 8081..
i will worry about resources after its running ..
can you explain the thin drivers..

[David Newton]

*WHERE* do you get a NullPointerException?

[ankur tyagi]

when i am calling the rs.next() function...
on line 26 of the code

[Devaka Cooray]

Make rset a local variable of View(String qry) method.

[ankur tyagi]

still not working man!!!

[Ben Souther]

ankur tyagi wrote:still not working man!!!

Please calm down.
It's not our job to fix your code.
Be grateful that people are trying to help you for free.

[Ben Souther]

Duplicate of:
https://coderanch.com/t/493572/Servlets/java/Null-Pointer-Exception

I've also noticed that you've already asked this in another forum.
I answered it there.
If you have further questions, please continue in the original thread.