I am writing a simple java based client application that will fetch published DCP and Pages from Tridion DB using 8.5 CIL APis. Tridion installation package folder "SDL Web 8.5\Content Delivery\roles\api\rest\java\lib" is included in the Java eclipse project for CIL references and it worked. But it has 43 jars and I do not want to refer all the jars if most of them are not required at all at compilation and Runtime. What are the CIL jars that are required mandatory (compile time + Runtime) in java client application. Thanks
They are all mandatory. Although there might be some scenarios where not all of them are actually used, it is impossible to predict what those scenarios are, and which jars it might be safe to remove. I therefore strongly recommend to keep them all.
Perhaps you will feel better if you take a look at the in-process version of the API, which has 82 jars instead of the 45 in the CIL. This was normal until not so very long ago. Count your blessings.