Help!!! JSP, java.lang.NoSuchMethodError (made me fed up)

Question

It is very very confused to me. The same code works very well under
http://localhost:8084 can not work on http://10.28.XX.XX:8080
It is a login program. It is very simple, to pass a userID and password to a JavaBean. If Bean checkes the user is valid, then telephone number will return. The follwing code is my fragment code..
Bean code..
public String getRoomNumber() {
return roomNumber;
public String getTelephoneNumber() {
return telephone;
JSP code
if(userIsExist && userIsValid)
userName = login.getUserName();
roomNumber = login.getRoomNumber();
division = login.getDivision();
telephone = login.getTelephoneNumber();
This code works very well under the localhost:8084, it can not work on the 10.28.XX.XX:8080
Also getUserName, getRoomNumber and getDivision can work, only getTelephoneNumber can not work.
It will gerate error
javax.servlet.ServletException: login.LoginBean.getTelephoneNumber()Ljava/lang/String;
     root cause
java.lang.NoSuchMethodError: login.LoginBean.getTelephoneNumber()Ljava/lang/String;
Very very strange.
Thanks for any helps

Answer 1

Thank you very much for your reply. You are correct.
Tomcat version on port 10.28.XX.XX:8048 is 5.0.19 and
on port 8080 is 5.0.28. I assuem maybe I install two
different Tomcat versions cause the problem. Thank you
sooooo much.
But I am still a bit confused, the same code can be
run on 5.0.19 and can't on 5.0.28.
DaanBut, if they are different versions of Tomcat, they are not the same instance of Tomcat. That means you are editing/testing with a JavaBean that you are not running with.
1) Make sure you put the Bean (and its package) in the WEB-INF/classes directory of the running Tomcat instance.
2)Try restarting the running Tomcat server (at http://10.28.xxx.xxx:8080) to be sure that the newest Bean is being used in the application.
3) Always deploy your applications (move from testing (localhost) to running server) using a WAR file. This will force the context to reload, and ensure you are using the most current version of the classes in the application. This is especially important in cases where you do no have access to restart the server as suggested in #2) If you need help on how to deploy via WAR, search these forums, and google.