Javadoc missing problem..!

I am designing a chat messenger using Java.

I need to use the cryptography extensions found in javax.crypto.* and java.security.*. Th开发者_开发问答e Javadoc viewer of NetBeans works fine with most methods in these packages. But some methods^* will not display the Javadoc:

Javadoc not found. Either Javadoc documentation for this item does not exist or you have not added specified Javadoc in the Java Platform Manager or the Library Manager.

How do I solve missing Javadoc?

^*Specifically, AlgorithmParameters.init() and Cipher.init() are missing.

Both methods have multiple overloads. Could it be caused by NetBeans not knowing which variant you want to see information for?