cache (Sun Java System Web Server 6.1 SP12 Programmer's Guide to Web Applications)

Sun Java System Web Server 6.1 SP12 Programmer's Guide to Web Applications

cache

Configures caching for web application components.

Subelements

The following table describes subelements for the cache element. The left column lists the subelement name, the middle column indicates the requirement rule, and the right column describes what the element does.

Table 6–25 cache Subelements


Element	Required	Description
cache-helper	zero or more	Specifies a custom class that implements the `CacheHelper` interface.
default-helper	zero or one	Allows you to change the properties of the default, built-in `cache-helper` class.
property	zero or more	Specifies a cache property, which contains a name and a value.
cache-mapping	zero or more	Maps a URL pattern or a servlet name to its cacheability constraints.

Attributes

The following table describes attributes for the cache element. The left column lists the attribute name, the middle column indicates the default value, and the right column describes what the attribute does.

Table 6–26 cache Attributes


Attribute	Default Value	Description
`max-entries`	`4096`	(optional) Specifies the maximum number of entries the cache can contain. Must be a positive integer.
`timeout-in-seconds`	30	(optional) Specifies the maximum amount of time in seconds that an entry can remain in the cache after it is created or refreshed. Can be overridden by a timeout element.
`enabled`	false	(optional) Determines whether servlet and JSP caching is enabled. Legal values are `on`, `off`, `yes`, `no`, `1`, `0`, `true`, `false`.

Properties

The following table describes properties for the cache element. The left column lists the property name, the middle column indicates the default value, and the right column describes what the property does.

Table 6–27 cache Properties


Property Name	Default Value	Description
`cacheClassName`	`com.sun.appserv.web.cache.LruCache`	Specifies the fully qualified name of the class that implements the cache functionality. See The Table 6–28
`MultiLRUSegmentSize`	`4096`	Specifies the number of entries in a segment of the cache table that should have its own LRU (least recently used) list. Applicable only if `cacheClassName` is set to `com.sun.appserv.web.cache.MultiLruCache`.
`MaxSize`	`unlimited; Long.MAX_VALUE`	Specifies an upper bound on the cache memory size in bytes (KB or MB units). Example values are 32 KB or 2 MB. Applicable only if `cacheClassName` is set to `com.sun.appserv.web.cache.BoundedMultiLruCache`.