@Override
    public Path getTempFile(final ResourceKey resourceKey) {
        // File gone !
        final ResourceItem resourceItem = currentFiles.get(resourceKey.getKey());
        if (resourceItem == null) {
            LOGGER.debug("resourceItem not found for resourceKey: {}", resourceKey);
            return null;
        }
        resourceItem.setLastAccessTime(Instant.now());
        LOGGER.debug("Returning resourceItem: {}", resourceItem);
        return resourceItem.getPath();
    }
Simple Store that gives you 1 hour to use your temp file before it deletes it.
stroom-resource/stroom-resource-impl/src/main/java/stroom/resource/impl/ResourceStoreImpl.java