When client accesses Forms application for the first time, java run-time classes bundled in JAR files are downloaded to client JRE cache. These files include frmall.jar,frmwebutil.jar and jacob.jar. Cumulative size of these files is more than 2mb. If your application has some additional JAR files for example, JAR file containing icons, more time will be required to download these additional files. On a slow connection, it creates a significant difference. Remember these files are downloaded only once when the application is accessed for the first time. JRE caches these files. when application is accessed next time, JRE reuses these files if no changes are made to these files on server. If JRE detects new version of JAR files on server, files are downloaded again.
We can reduce this download time by keeping a copy of these files on client side prior to accessing the application. If we place these file on the default CLASSPATH of JRE , JRE use these files form client side instead of downloading it from server. Suppose JRE is installed in C: drive, you can place these files in following directory,
C:\Program Files\Java\jre6\lib\ext
Now when you access Forms 11g application, JRE loads all required JAR files from \ext directory. This saves significant time on a slow connection.
You can get the jar files from Application server also from following location
/u01/oracle/middleware/Oracle_FRHome1/forms/java
Reference :
http://www.exploreoracle.com/2010/07/02/minimizing-forms-11g-application%E2%80%99s-first-time-startup-overhead/
