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WebDAV Construction Kit (WCK)

The WebDAV Construction Kit (WCK) is a framework for easy integration of the WebDAV interface into all kinds of Java software. No special knowledge of Slide or WebDAV is required to make the usual Windows, Mac and Linux clients work with your server system. These are the main features:

  • adapter for Slide's complex storage mechanism to a simple API
  • reference implementation and default configuration to a complete and simple file system store
  • JAAS authentication framwork to completely bypass Slide's security mechanism; instead the user base and access rights of your server system is used
  • generic pooling framwork for connections to your server system using commons pool
  • build script that compiles WCK to both Slide 2.1 and the current Slide head

Important: Currenly, WCK is avaiable from CVS only. Check out the WCK Quick start page for information how to get it working.

Disclaimer #1: WCK has not been officially released, yet. This means when you use it consider yourself at most as a beta tester. Feedback is very welcome!

Disclaimer #2: WCK makes WebDAV integration easier. This does not mean it can do magic! While no special knowledge of Slide and WebDAV is required you will need good to excellent knowledge of cvs, ant, Java, Tomcat, XML configuration files, property files and a general idea of how to build software. Using WCK is no act of configuration, but involves serious programming.

Disclaimer #3: WCK has been developed and tested with Tomcat 5.0.28. Any other Tomcat version, especially 4.x, is not recommended. If you happen to make WCK work on any other web container or application server please report back and tell us what was involved to make it work.

WCK emerged out of the experience that Slide's storing system is most flexible and generic, but too complex for many people who just want to add the WebDAV interface to their systems. Additionally, it contains a JAAS login module that allows you to bypass Slide's user managerment and the complete internal access checking. All this is done by your proprietary system. This, however, is optional to you.

It is important to understand that all this works only when you access Slide through its WebDAV interface and only if you restrict yourself to the core WebDAV methods. It is likely not to work when you use the native Slide interface. It will not work with ACL, BIND, SEARCH and DeltaV methods.

The main interfaces

To make Slide work as your WebDAV layer you will have to implement a single interface: It contains some call back methods which do not use any Slide classes except for the exceptions, which I thought are pretty obvious and thus it would have been silly to more or less clone them. Here they are for a short reference - detailed information can be found in the Javadocs of the respective classes:

  • begin, commit, rollback: begins, commits, aborts a request / transaction
  • objectExists, isFolder, isResource: existence checks, collection vs. content checks
  • createFolder, createResource: creation of a collection or a content resource
  • removeObject: deletion of a collection or a content resource
  • setResourceContent, getResourceContent: storing and retrieval of a content resource
  • getLastModified, getCreationDate, getResourceLength: retrieval of basic meta data
  • getChildrenNames: retrieval of the children of a collection

This is all Slide and WCK need to make basic WebDAV operations work. There are optional extension interfaces that add full property access and locking if your system supports them.

The second main interface is even simpler and allows you to login into Slide using your proprietary user database. The glue code will pass session and connection information to your store as well. All this allows to effectively bypass Slide's security code and leave this to your system. All you have to implement are three methods of the org.apache.slide.simple.authentication.SessionAuthenticationManager:

  • getAuthenticationSession (2x one with user/password one with user only): asks if a certain user exists and authenticated itseld correctly and if so an object that allows access to your system, i.e. a session or connection or anything similiar, is passed back; in case the user has already authenticated correctly before only the user with no password is passed
  • closeAuthenticationSession: closes the session / terminates the connection to your system

Using this interface the glue code finds out if a user exists and authenticated itself correctly and passes all relevant information to the basic WebDAV store for you to make authenticated requests to your system later. All this is optional, you still can use Slide's internal security with your WebDAV store if this is not appropriate for you. For your convenience there also is a connection pool framework at org.apache.slide.simple.authentication.AbstractPoolingConnectionManager available.

Reference Implementation

For the store, the session manager and the pooling connection manager there are reference implementations to the file system to help you get going. However, the ones for sessions and connection management are dummies only as the file system neither needs sessions nor connections. You can find the code in the org.apache.slide.simple.reference package.

The reference implementation of the store part and also parts of the glue code are heavily inspired by the work of Alon who provided the simple file store to us - so credit goes to Alon. The new implementation of the file store extends Alon's in adding arbitrary properties (optional) and locks (optional) and proper handling of access violations.

Building and Deploying

WCK works with both the current versions of Slide 2.1 and the CVS HEAD and comes with a build script that creates a full working web archive to be deployed in Tomcat. Which one it will compile to and package with is to be determined in

Next to the basic settings in you can define additional paths of source and libraries and other settings to adapt WCK to your own project. Copy and uncomment and set the appropriate properties:

  • domain: the path of the Domain.xml to use
  • jaas.config: the JAAS configuration that contains the reference to your session manager and optionally more parameters
  • special Slide properties can that selectively be switch on and off; the default switches off Slide's internal security as your own should be used, versioning and search are switched off as well as WCK does not support them

If you do not change anything the defaults from the conf directory and the reference implementations will be used.

A Quick start page with the default implementations can be found here.

Where to go from here?

A dedicated place for user comments and information is in the Slide Wiki pages. Questions are welcome in the Slide user mailing list. Be sure to subscribe to the list before posting anything as it will not come through otherwise.

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