javax.cache

Interface ExpiryPolicy<K,V>

Type Parameters:

K - the type of keys

V - the type of values

All Known Implementing Classes:

ExpiryPolicy.Accessed, ExpiryPolicy.Default, ExpiryPolicy.Modified

public interface ExpiryPolicy<K,V>

Defines functions to determine when cache entries will expire based on creation, access and modification operations.

Each of the functions return a Configuration.Duration that of which specifies the amount of time that must pass before a cache entry is considered expired. This Configuration.Duration is often called a "time-to-live", commonly abbreviated to simply "TTL".

Author:

Brian Oliver

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ExpiryPolicy.Accessed<K,V> A ExpiryPolicy that defines the expiry Configuration.Duration of a Cache Entry based on the last time it was accessed.
static class	ExpiryPolicy.Default<K,V> The default ExpiryPolicy specifies that Cache Entries won't expire.
static class	ExpiryPolicy.Modified<K,V> A ExpiryPolicy that defines the expiry Configuration.Duration of a Cache Entry based on the last time it was modified.

Method Summary

Methods

Modifier and Type	Method and Description
Configuration.Duration	getTTLForAccessedEntry(Cache.Entry<? extends K,? extends V> entry, Configuration.Duration duration) Gets the time-to-live before the accessed Cache.Entry is considered expired.
Configuration.Duration	getTTLForCreatedEntry(Cache.Entry<? extends K,? extends V> entry) Gets the time-to-live before the newly Cache.Entry is considered expired.
Configuration.Duration	getTTLForModifiedEntry(Cache.Entry<? extends K,? extends V> entry, Configuration.Duration duration) Gets the time-to-live before the modified Cache.Entry is considered expired.

Method Detail

getTTLForCreatedEntry

Configuration.Duration getTTLForCreatedEntry(Cache.Entry<? extends K,? extends V> entry)

Gets the time-to-live before the newly Cache.Entry is considered expired.

This method is called after a Cache.Entry is created, but before the said entry is added to a cache, to determine the Configuration.Duration before the said entry expires. If a Configuration.Duration.ZERO is returned the Cache.Entry is considered to be already expired and will not be added to the Cache.

Should an exception occur while determining the Duration, an implementation specific default Duration will be used.

Parameters:

entry - the cache entry that was created

Returns:

the duration until the entry expires

getTTLForAccessedEntry

Configuration.Duration getTTLForAccessedEntry(Cache.Entry<? extends K,? extends V> entry,
                                            Configuration.Duration duration)

Gets the time-to-live before the accessed Cache.Entry is considered expired.

This method is called after a Cache.Entry is accessed to determine the Configuration.Duration before the said entry expires in the future. If a Configuration.Duration.ZERO is returned the Cache.Entry will be considered expired for future access.

Should an exception occur while determining the Duration, an implementation specific default Duration will be used.

Parameters:

entry - the cache entry that was accessed

duration - the current Configuration.Duration before the entry expires

Returns:

the duration until the entry expires

getTTLForModifiedEntry

Configuration.Duration getTTLForModifiedEntry(Cache.Entry<? extends K,? extends V> entry,
                                            Configuration.Duration duration)

Gets the time-to-live before the modified Cache.Entry is considered expired.

This method is called after a Cache.Entry is modified to determine the Configuration.Duration before the updated entry expires. If a Configuration.Duration.ZERO is returned the Cache.Entry is considered already expired.

Should an exception occur while determining the Duration, an implementation specific default Duration will be used.

Parameters:

entry - the cache entry that was modified

duration - the current Configuration.Duration before the updated entry expires

Returns:

the duration until the entry expires