Interface UserCache
- All Known Implementing Classes:
NullUserCache,SpringCacheBasedUserCache
UserDetails objects.
Implementations should provide appropriate methods to set their cache parameters (e.g.
time-to-live) and/or force removal of entities before their normal expiration. These
are not part of the UserCache interface contract because they vary
depending on the type of caching system used (in-memory, disk, cluster, hybrid etc.).
Caching is generally only required in applications which do not maintain server-side state, such as remote clients or web services. The authentication credentials are then presented on each invocation and the overhead of accessing a database or other persistent storage mechanism to validate would be excessive. In this case, you would configure a cache to store the UserDetails information rather than loading it each time.
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Method Summary
Modifier and TypeMethodDescriptiongetUserFromCache(String username) Obtains aUserDetailsfrom the cache.voidputUserInCache(UserDetails user) Places aUserDetailsin the cache.voidremoveUserFromCache(String username) Removes the specified user from the cache.
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Method Details
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getUserFromCache
Obtains aUserDetailsfrom the cache.- Parameters:
username- theUser.getUsername()used to place the user in the cache- Returns:
- the populated
UserDetailsornullif the user could not be found or if the cache entry has expired
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putUserInCache
Places aUserDetailsin the cache. Theusernameis the key used to subsequently retrieve theUserDetails.- Parameters:
user- the fully populatedUserDetailsto place in the cache
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removeUserFromCache
Removes the specified user from the cache. Theusernameis the key used to remove the user. If the user is not found, the method should simply return (not thrown an exception).Some cache implementations may not support eviction from the cache, in which case they should provide appropriate behaviour to alter the user in either its documentation, via an exception, or through a log message.
- Parameters:
username- to be evicted from the cache
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