Package com.microstrategy.utils.cache

Class FileCacheBase

java.lang.Object

com.microstrategy.utils.cache.CacheBase

com.microstrategy.utils.cache.CustomizationsAwareCache

com.microstrategy.utils.cache.FileCacheBase

All Implemented Interfaces:

Cache, java.util.Observer

Direct Known Subclasses:

ResourceCache

public abstract class FileCacheBase
extends CustomizationsAwareCache

The FileCacheBase is the base class for cached objects that depend on a single file, that is, the file they depend on cannot be customized through the plug-ins infrastructure, nor can it internally depend on other configuration files.

It's load method will call the doLoad(com.microstrategy.utils.cache.CacheHint) and save the file's ModificationTime in a table. When reload is call it will compare the current file's ModificationTime against the value in the table and only if different will call load(com.microstrategy.utils.cache.CacheHint) again.

Since:

MicroStrategy Web 9.0.0

Field Summary

Fields inherited from class com.microstrategy.utils.cache.CacheBase

alias, DEFAULT_FILE_REFRESH_TIME, DEFAULT_REFRESH_TIME, DEFAULT_STATISTIC_TIME, DEFAULT_SYS_TIMEOUT, DEFAULT_USER_TIMEOUT, NO_KEY, NO_REFRESH, NO_STATISTIC, NO_TIMEOUT

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	FileCacheBase(java.lang.String cacheName)	Base constructor, it will register the Cache in the CacheRegistry and set is refresh time to CacheBase.DEFAULT_FILE_REFRESH_TIME

Method Summary

Modifier and Type	Method	Description
protected abstract java.lang.Object	doLoad(CacheHint hint)	This abstract method is called by the load method to perform the actual loading.
protected java.lang.Object	getKey(CacheHint hint)	Returns the key of the cache element based on the hint.
protected java.lang.String	getPath(CacheHint hint)	Returns the path for the given hint.
protected java.lang.Object	load(CacheHint hint)	Loads an element from a file and keeps track of its last modification time.
protected java.lang.Object	reLoad(CacheHint hint, java.lang.Object ob)	Checks if the file corresponding to the hint has changed (by comparing its last modification time with the value stored by the load method), and if the same, just returns the same object, otherwise it will call delegate tot he load(com.microstrategy.utils.cache.CacheHint) method.

Methods inherited from class com.microstrategy.utils.cache.CustomizationsAwareCache

update

Methods inherited from class com.microstrategy.utils.cache.CacheBase

canUpdate, clear, close, configure, contains, delete, get, getName, getRefreshTime, getStatisticTime, getTimeout, getWithoutRefresh, logStatistic, onHintClose, onTimer, put, refresh, remove, save, setRefreshTime, setStatisticTime, setTimeout, size, store, unLoad

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileCacheBase

protected FileCacheBase(java.lang.String cacheName)

Base constructor, it will register the Cache in the CacheRegistry and set is refresh time to CacheBase.DEFAULT_FILE_REFRESH_TIME

Parameters:

cacheName - The name (id) of the Cache.

Method Detail

load

protected java.lang.Object load(CacheHint hint)
                         throws CacheException

Loads an element from a file and keeps track of its last modification time. The actual loading of the element is delegated to the doLoad(com.microstrategy.utils.cache.CacheHint) method.

Specified by:

load in class CacheBase

Parameters:

hint - the hint object.

Returns:

the object or null.

Throws:

CacheException - if somethig gos wrong.

reLoad

protected java.lang.Object reLoad(CacheHint hint,
                                  java.lang.Object ob)
                           throws CacheException

Checks if the file corresponding to the hint has changed (by comparing its last modification time with the value stored by the load method), and if the same, just returns the same object, otherwise it will call delegate tot he load(com.microstrategy.utils.cache.CacheHint) method.

Overrides:

reLoad in class CacheBase

Parameters:

hint - the hint object.

Returns:

the object or null.

Throws:

CacheException - if somethig gos wrong.

getKey

protected java.lang.Object getKey(CacheHint hint)
                           throws CacheException

Returns the key of the cache element based on the hint. In this scenario, the hint itself is the key.

Specified by:

getKey in class CacheBase

Parameters:

hint - the hint object.

Returns:

the key

Throws:

CacheException - if somethig gos wrong.

getPath

protected java.lang.String getPath(CacheHint hint)

Returns the path for the given hint. This implementation simply uses the hint value.

doLoad

protected abstract java.lang.Object doLoad(CacheHint hint)
                                    throws CacheException

This abstract method is called by the load method to perform the actual loading. In this method, subclasses needs to load the file and parse it, and return the object they actually want cached.

Throws:

CacheException