@Path("{identifier}")
    public ActivityRecordResource getRecord(@PathParam("identifier") String identifier)
                throws GuacamoleException {

        InternalRecordType record = history.get(identifier);
        if (record == null)
            throw new GuacamoleResourceNotFoundException("Not found: \"" + identifier + "\"");

        return new ActivityRecordResource(record, toExternalRecord(record));

    }
Retrieves record having the given identifier from among the set of
activity records stored within the underlying ActivityRecordSet.

@param identifier
    The unique identifier of the record to retrieve.

@return
    A resource representing the record having the given identifier.

@throws GuacamoleException
    If an error occurs while locating the requested record, or if the
    requested record cannot be found.
guacamole/src/main/java/org/apache/guacamole/rest/history/ActivityRecordSetResource.java