Problem connecting RMI-Server using a servlet

Question

Hi All..
I have a RMI-client server model woring fine in AIX box.I am currently in a need to create one web client(may be with servlet or JSP).
I wrote a sample servlet which try to connect to the RMI server. But when I run the servlet Its simply try to connect and then wait for unlimited time,not even print any exception/error.
Both my RMI sevrer and Tomcat are in the same box.
I am sending the servlet code for your reference.
import java.rmi.*;
import java.rmi.registry.Registry;
import java.rmi.registry.LocateRegistry;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import ir77.mon.engine.*;
public class WebClient extends HttpServlet
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
XmlServerIntf xmlServerIntf = null;
PrintWriter out = res.getWriter();
res.setContentType("text/plain");
try{
out.println("Connecting to server......");
//Seems this one is sufficient.(either this code or the below one)
//String strServerUrl = "rmi://" + "192.168.100.22" + "/ir77.mon.engine";
//xmlServerIntf = (XmlServerIntf) Naming.lookup(strServerUrl);
//Try with this one also
Registry reg = LocateRegistry.getRegistry("192.168.100.22", 2004);
xmlServerIntf = (XmlServerIntf) reg.lookup("rmi://192.168.100.22/ir77.mon.engine");
out.println("Connected to server");
catch (Exception e){
System.out.println("Exception in WebClient"+e);
when I run the servlet in the browser with "http://192.168.100.22:8080/WebClient" its simply prints " Connecting to server......" and waits.
Note : 192.168.100.22 - where my rmi server starts and 2004 -where I created by rmiregistry.I created it using LocateRegistry.createRegistry(2004);
I have tried starting tomcat with "-security" option too but no responds as well.
Do I have to provide some grant permission in catlina.policy file?If yes what?
currently I have tried with giving all permission..
Do I need to change the RMI server code?
Any help will be highly appreciated....

Answer 1

Hi genady,
Oh....Ya I like to...I thought no body was interested...as I didn't get any reply from anybody....
Well The first thing is that with the look up method in the servlet
it should be like :
Registry reg = LocateRegistry.getRegistry("ip address of the rmi server", port number);
RMIServerInterface = (type cast with RMIServerInterface) reg.lookup("rmi binding string");
Now you are able to get the server interface object & you can call any method.
Next you have to provide the grant permission in the catalina.policy file to the folder where you have your application like....
grant codeBase "file:${catalina.home}/webapps/ROOT/WEB-INF/classes/-" {
permission java.security.AllPermission;
Or you can give specific permissions also.
Finally you have to run the tomcat as : $catalina.sh start -security
Note: One more thing you have to keep in mind that's the structure of your application. ie com.mon.yourapp.......u have to create the same structure in tomcat's classes folder .
Its done...........