Hi Kavitha ,
You need to import these jar or lib files in build path of your project to get your code compiled . Go to Package explorer view in designer → Right click on your project in which your java code which updates the excel file resides and click on build path → Go to libs tab → add external jars and add above all jar files which you placed in “package/code/jars folder” .
Once designer loads all built in classes in project space this code will get compiled .
Thanks
Shrikant