org.w3c.tools.resources.store
Interface ResourceStore

All Known Implementing Classes:

ResourceStoreImpl

public interface ResourceStore

A resource store implements persistency for a set of resources. A resource store may implement a number of strategies along different axis, for example:

• It may connect to some database to get the resource attributes.
• It may restrict the classes of the resource it handles (for security reasons), by using a specific class loader.
• It may implement some caching scheme, to keep memory requirements low.
• It may be distributed (eg using a ResourceStoreStub in the client, but providing access to a server-side resource store.).

Method Summary

boolean	acceptUnload() Can this resource store be unloaded now ? This method gets called by the ResourceStoreManager before calling the shutdown method, when possible.
void	addResource(Resource resource) Add this resource to this resource store.
java.util.Enumeration	enumerateResourceIdentifiers() Enumerate all the resources saved in this store.
java.lang.String	getIdentifier() Get the identifier for that store.
int	getVersion() Get the version of that resource store.
boolean	hasResource(java.lang.String identifier) Check for the existence of a resource in this store.
void	initialize(ResourceStoreManager manager, java.lang.Object token, java.io.File repository, Serializer serializer) This resource store is being built, initialize it with the given arg.
Resource	loadResource(java.lang.String identifier, java.util.Hashtable defs) Restore the resource whose name is given.
Resource	lookupResource(java.lang.String identifier) Get this resource, but only if already loaded.
void	markModified(Resource resource) Mark this resource as modified.
void	removeResource(java.lang.String identifier) Remove this resource from the repository.
void	renameResource(java.lang.String oldid, java.lang.String newid) Rename a given resource.
void	save() Save this store.
void	saveResource(Resource resource) Stabilize the given resource.
void	shutdown() Shutdown this store.

Method Detail

getVersion

int getVersion()

Get the version of that resource store. Version numbers are used to distinguish between pickling format. A resource store implementator has the duty of bumping the returned number whenever it's archiving format changes. Resource stores that relies on some external archiving mechanisms (such as a database), may return a constant.

Returns:

An integer version number.

getIdentifier

java.lang.String getIdentifier()

Get the identifier for that store.

Returns:

A uniq store identifier, as a String.

loadResource

Resource loadResource(java.lang.String identifier,
                      java.util.Hashtable defs)
                      throws InvalidResourceException

Restore the resource whose name is given. This method doesn't assume that the resource will actually be restored, it can be kept in a cache by the ResourceStore object, and the cached version of the resource may be returned.

Parameters:

identifier - The identifier of the resource to restore.

defs - Default attribute values. If the resource needs to be restored from its pickled version, this Hashtable provides a set of default values for some of the attributes.

Returns:

A Resource instance, or null.

Throws:

InvalidResourceException - If the resource could not be restored from the store.

lookupResource

Resource lookupResource(java.lang.String identifier)

Get this resource, but only if already loaded. The resource store may (recommended) maintain a cache of the resource it loads from its store. If the resource having this identifier has already been loaded, return it, otherwise, return null.

Parameters:

identifier - The resource identifier.

Returns:

A Resource instance, or null.

saveResource

void saveResource(Resource resource)

Stabilize the given resource.

Parameters:

resource - The resource to save.

addResource

void addResource(Resource resource)

Add this resource to this resource store.

Parameters:

resource - The resource to be added.

removeResource

void removeResource(java.lang.String identifier)

Remove this resource from the repository.

Parameters:

identifier - The identifier of the resource to be removed.

renameResource

void renameResource(java.lang.String oldid,
                    java.lang.String newid)

Rename a given resource.

Parameters:

oldid - The olde resource identifier.

newid - The new resource identifier.

markModified

void markModified(Resource resource)

Mark this resource as modified.

Parameters:

resource - The resource that has changed (and will have to be pickled some time latter).

acceptUnload

boolean acceptUnload()

Can this resource store be unloaded now ? This method gets called by the ResourceStoreManager before calling the shutdown method, when possible. An implementation of that method is responsible for checking the acceptUnload method of all its loaded resource before returning true, meaning that the resource store can be unloaded.

Returns:

A boolean true if the resource store can be unloaded.

shutdown

void shutdown()

Shutdown this store.

save

void save()

Save this store.

enumerateResourceIdentifiers

java.util.Enumeration enumerateResourceIdentifiers()

Enumerate all the resources saved in this store.

Returns:

An enumeration of Strings, giving the identifier for all the resources that this store knows about.

hasResource

boolean hasResource(java.lang.String identifier)

Check for the existence of a resource in this store.

Parameters:

identifier - The identifier of the resource to check.

Returns:

A boolean true if the resource exists in this store, false otherwise.

initialize

void initialize(ResourceStoreManager manager,
                java.lang.Object token,
                java.io.File repository,
                Serializer serializer)

This resource store is being built, initialize it with the given arg.

Parameters:

manager - The ResourceStoreManager instance that asks yourself to initialize.

token - The resource store manager key to that resource store, this token should be used when calling methods from the manager that are to act on yourself.

repository - A file, giving the location of the associated repository.