org.biomoby.client
Interface SimpleCache

All Known Subinterfaces:

SimpleFileCache

All Known Implementing Classes:

CentralCachedCallsImpl, CentralDigestCachedImpl, CentralDigestCachedSimpleImpl, CentralDigestImpl, CentralImpl, FileCache, ServletFileCache

public interface SimpleCache

An interface defining basic operation for caching data.

Version:

$Id: SimpleCache.java,v 1.4 2005/05/19 15:57:25 senger Exp $

Author:

Martin Senger

Method Summary

String	createId(String rootName, String semanticType, String syntaxType, long lastModified, Properties props) Create a unique ID from the given parameters.
boolean	existsInCache(String id) Is the object identified by its 'id' already cached?
Object	getContents(String id) Return 'data' identified by 'id'.
void	removeFromCache(String id) Remove cached object identified by its 'id' from the cache.
void	setContents(String id, Object data) Store/cache 'data' identified by 'id'.

Method Detail

createId

String createId(String rootName,
                String semanticType,
                String syntaxType,
                long lastModified,
                Properties props)

Create a unique ID from the given parameters. The ID is used to identify a cached object. Depending on the implementation it can be a filename, a database primary key, or something else. Its important characteristic, however, is that given the same set of properties describing the cached object, the same ID is always created.

Parameters:

rootName - is some high level name of the cached object

semanticType - is yet another feature of the cached object

syntaxType - is another property of the cached object (e.i. it may be used as the file name suffix if the cache is implemented as a filesystem)

lastModified - is time in millis indicating when the cached object was created or modified

props - are all remaining properties identifying the cached object

Returns:

a unique ID that can be used in other methods defined in this interface in order to identify the same cached object

existsInCache

boolean existsInCache(String id)

Is the object identified by its 'id' already cached?

Parameters:

id - a unique ID of the cached (or possibly cached) object

Returns:

true if the object identified by 'id' already exists in this cache

getContents

Object getContents(String id)
                   throws IOException

Return 'data' identified by 'id'.

Parameters:

id - a unique ID of the object being returned

Returns:

data previously stored under 'id'; or null if such data do not exist

Throws:

IOExcepiton - if the retrieving failed

IOException

setContents

void setContents(String id,
                 Object data)
                 throws IOException

Store/cache 'data' identified by 'id'.

Parameters:

id - a unique ID of the object being stored

data - are being stored

Throws:

IOExcepiton - if the storing failed

IOException

removeFromCache

void removeFromCache(String id)
                     throws IOException

Remove cached object identified by its 'id' from the cache.

Parameters:

id - a unique ID

Throws:

IOException - if the object exists but cannot be removed (meaning that it does not raise any exception if the object is not anymore in the cache)