Oracle Forms Community - Pluggable Java Components & Java Beans' library

Purpose

Here is a Java Bean from Gert Poel, to Drop an external file within the Forms applications.

The Java source
 

     FileDrop.java   FileDropBean.java

The implementation class of the Java Bean

     oracle.forms.gp.FileDropBean

The event fired by the Java Bean


 DROP


The full filemane is transmitted in the EVENT_MSG parameter.

DECLARE
 l_eventName varchar2(30) := :system.custom_item_event;
 l_eventValues ParamList;
 l_eventValueType number;
 l_event_msg VARCHAR2(255);
BEGIN
   IF l_eventName = 'DROP'
   THEN
      l_eventValues := get_parameter_list(:system.custom_item_event_parameters);
      get_parameter_attr(l_eventValues,'EVENT_MSG',l_eventValueType, l_event_msg);
      IF :system.record_status <> 'NEW'
      THEN
         create_record;
      END IF;
      :ctrl.file_location := l_event_msg;
   END IF;
END;

When you migrate to the latest Forms version (10.1.2.3 or 11) and try using a JavaBean created with an older Forms version, you can get the following error, at runtime, in the Java Console:

Exception in thread "thread applet-oracle.forms.engine.Main-1" java.lang.NoSuchMethodError: oracle.forms.handler.IHandler.getApplet()Ljava/applet/Applet

The reason is you try to use a Java Bean compiled with an older Forms JAR file, like f90all.jar.
So, to correct the issue, you have to change the Java code then re-create the JAR file:

private Main         formsMain = null;

Replace:

    formsMain  =  (Main) handler.getApplet();

by:

     // getting the Forms Main class
    try{
      Method method = handler.getClass()
                     .getMethod("getApplet", new Class[0]);
      Object applet = method.invoke(handler, new Object[0]);
      if (applet instanceof Main) {
         formsMain = (Main)applet;
      }    
    }catch(Exception ex) {;} 

Then create and deploy the new JAR file to your /forms/Java folder.