but it works for me when I run the same with developer suite,Yes, this would work because your OC4J Container - the equivilent of an Application Server (AS) is running on your workstation. However, when you run this form from your actual AS, the Java Applet will run on the AS not your client desktop. This is the basic topology of Web Forms. The form runs on the AS and the UI is displayed on the Client. The Form does not actually run on the Client. Does that make sense? Take a look at An Overview of Oracle Forms Server Architecture for detailed information on how Web Forms work.
...I have imported the client java file into the forms, I can see the client package body and spec.It sounded like you were implementing a Pluggable Java Component (PJC) not a Java Bean.