How to make sure that no one reads from Ehcache Ob

问题:

I want to store data into the Cache using EhCache, but if I try to access the data before data has been populated into the Cache, I get NULL POINTER exception. How can I make sure that Data is not read from the cache until and unless data has been stored into the Cache?

回答1:

What you are requesting will make cache usage very problematic.

If you always block on a missing entry, any eviction or expiry will put you in the same situation as having an empty cache / missing mapping.

However, using cache-through might be a better way to look at the problem. It would leave the loading of the mapping to the cache itself making sure you never get a null result (unless that key does not exist in the backing store).

See documentation for more information on that option.