org.w3c.tools.resources
Interface ResourceReference

All Known Implementing Classes:

DummyResourceReference

public interface ResourceReference

Resolving a resource provides back a resource reference. Resource references are the basis for handling an eventual cache between the store of the resource and its memory image (ie the resource instance).

All resource spaces must provide some notion of resource reference.

A typical access to a resource looks like:

 ResourceReference rr = space.lookup("/x/y/z");
 try {
    Resource r = rr.lock();
    // Fiddle with the resource:
    r.setValue("foo", new Integer(10));
 } catch (InvalidResourceException e) {
   System.out.println(e.getMessage());
 } finally {
    // Make sure to unlock the reference:
    rr.unlock();
 

Method Summary

boolean	isLocked() Is that resource reference locked ?
Resource	lock() Lock the refered resource in memory.
int	nbLock() How many locks?
void	unlock() Unlock that resource from memory.
Resource	unsafeLock() Lock the refered resource in memory.
void	updateContext(ResourceContext ctxt) update the cached context of that reference.

Method Detail

lock

Resource lock()
              throws InvalidResourceException

Lock the refered resource in memory.

Returns:

A real pointer to the resource.

Throws:

InvalidResourceException - is thrown if the resource is invalid (has been deleted or everything else).

unsafeLock

Resource unsafeLock()
                    throws InvalidResourceException

Lock the refered resource in memory. NOTE, this version is NOT using a synchronized call and therefore must be used with extreme caution. Basically it must be used only when a backward locking is needed

Returns:

A real pointer to the resource.

Throws:

InvalidResourceException - is thrown if the resource is invalid (has been deleted or everything else).

unlock

void unlock()

Unlock that resource from memory.

isLocked

boolean isLocked()

Is that resource reference locked ?

Returns:

a boolean.

nbLock

int nbLock()

How many locks?

Returns:

an int.

updateContext

void updateContext(ResourceContext ctxt)

update the cached context of that reference.

Parameters:

ctxt - the new ResourceContext.