Introduction to SyMBA Web Services

Web services (WS) are used to make simple applications available as web applications (more information can be found here and here ). SyMBA makes use of Crossfire (CXF) in a Maven 2 plugin to build web services into a war that can be loaded into a Tomcat server. CXF is "an open source services framework [...] that helps you build and develop services using frontend programming APIs, like JAX-WS. These services can speak a variety of protocols such as SOAP, XML/HTTP, RESTful HTTP, or CORBA and work over a variety of transports such as HTTP, JMS or JBI."

Services Currently Available

Currently, SyMBA has 3 services with a total of 4 methods. All of these services relate to the LSIDs contained within SyMBA, and via these LSIDs perform a number of useful tasks.

  • LsidAssigner

    • assignLsid(). Create a new LSID.

  • LsidResolver

    • getAvailableServices(). Check that the available web services can deal with your LSID.

  • LsidDataRetriever

    • getMetadata(). Get some information about an LSID.

    • getData(). Get the data pointed to from an LSID.

Deviations From the LSID Specification.

The SyMBA LSID web services mentioned currently implement only those parts of the specification in active use within SyMBA (LSID specification ). In particular, these web services (as well as the general SyMBA API) implement LSIDs as Java Strings rather than as complex objects. SyMBA developers have found no need to use the parameters and properties portion of the specification, and wish to keep the SyMBA implementation as straightforward to use and understand as possible. Additionally, only those methods from the LSID specification that SyMBA developers have found a use for have been implemented at this stage. If you wish a more complete implementation, please email the mailing list and let us know what you need.

LSID Metadata Compared With FuGE-OM Metadata

There are differences between what the LSID specification describes as "metadata", and what the FuGE-OM means by the same term.

LSID metadata is information about the LSID , as opposed to LSID Data, which is the information associated with the LSID. LSID metadata tells you things about the status of the LSID: it includes a expiration timestamp (which, if null, means the LSID does not expire), and any other information that the supplier of the LSID wishes to provide. The LSID metadata, unlike the LSID data, can change at any time, and is not required to always return the same thing. In SyMBA, the timestamp will always be null, and the metadata currently returns an RDF-formatted object with a title and a value. At the moment, this object is just the LSID of the latest version of Identifiable object associated with the same Endurant object as the LSID you provided.

FuGE metadata is every bit of information stored in the FuGE-OM structure, whereas the data is the actual data file(s) associated with this metadata. Each Identifiable object in FuGE (which includes the reference to the data file(s)) is marked with an LSID. Therefore, to retrieve FuGE metadata concerning a given LSID, call the getData() method in the LSID Data Retrieval WS. To retrieve the data file itself, you also call the getData() method, but provide the LSID that points to the raw data rather than the LSID that points to one of the structures that forms the FuGE-OM.