Server-Side Eclipse is the latest effort to use the Eclipse architecture and the OSGi platform to develop modular web applications. This tutorial introduces the technology, concepts and tools needed to develop Eclipse based web applications. A significant portion of the tutorial will be spent on hands-on activities with the aim of bringing attendees up to speed quickly with setting up the workspace, developing and deploying applications as well as looking at debugging and monitoring techniques.

1. Building Server-Side Eclipse based web
applications
Tutorial
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
1 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

2. The authors
Jochen Hiller Simon Kaegi
Deutsche Telekom AG, Germany IBM Rational Software, Canada
jo.hiller@googlemail.com simon_kaegi@ca.ibm.com
Equinox, E4 Committer
Gunnar Wagenknecht
AGETO, Germany
gunnar@wagenknecht.org
Eclipse Committer
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
2 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

3. Overview
• Introduction to Server-Side Eclipse
• Developing Server-Side Eclipse applications
• Deploying Server-Side Eclipse applications
• Monitoring and Debugging Server-Side Eclipse
applications
• Summary
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
3 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

4. What is Server-Side Eclipse (SSE)?
• Recognition… that many of the features that have made RCP successful are
equally applicable in server-side contexts.
Standardized component model (OSGi)
Pervasive extensibility – Extension Registry
Runtime provisioning
• Integration... with existing server-side infrastructure and technologies
J2EE Application Servers
Servlets and JSPs
Application Frameworks
…
• Jeff McAffer stated at EclipseCon 2007, Equinox BOF:
Server-Side Eclipse is a concept, a marketing name, to illustrate possible usage scenarios (like
RCP).
• The new top level project Eclipse Runtime is an umbrella project for a lot of
server-related projects
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
4 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

5. What motivates developers to use SSE?
Web developer RCP developer Infrastructure developer
JavaTM EE RCP application
application application framework
+ component model + server support + component model
+ use 3rd party plug-ins + re-use plugins • modular
+ distributed • flexible
applications • dynamic
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
5 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

6. SSE Based Web Applications
• Component based (Bundles)
• Use the OSGi HttpService (Servlet API)
Explicitly (code) or declaratively (extension registry)
• Consistent development story independent of
deployment constraints
Support for an embedded HttpService
Support for running embedded in Application Servers
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
6 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

7. Overview
• Introduction to Server-Side Eclipse
• Developing Server-Side Eclipse applications
• Deploying Server-Side Eclipse applications
• Monitoring and Debugging Server-Side Eclipse
applications
• Summary
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
7 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

8. Integrating Java EE with the OSGi HttpService
• Replaces web deploy descriptor (e.g. “web.xml”)
• URL mapping differences
• Servlet API support
ServletContext / HttpContext differences
Does not provide “direct” support for Filters, Listeners.
• Dynamic Registration
void registerResources(String alias, String name, HttpContext context)
void registerServlet(String alias, Servlet servlet, Dictionary initparams, HttpContext context)
void unregister(String alias)
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

9. URL Mapping Differences
void registerResources(String alias, String name, HttpContext context)
• “alias” roughly equivalent to <url-mapping>
alias of “/myContent” is equivalent to
<url-mapping>
/myContent/*
</url-mapping>
• “name” provides a base path when looking up resources in the
HttpContext.
Supported in Equinox
• No support for extension mappings Syntax is:
{path}/*.jsp
• No implicit welcome file support
eg. mapping “/” to “/index.html”
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

10. HttpContext
• Maps 1-1 to a ServletContext Method Summary
String getMimeType(String name)
• Allows implementation of custom
HttpContext
URL getResource(String name)
• MIME type retrieval boolean handleSecurity(
• resource retrieval HttpServletRequest request,
HttpServletResponse response)
• authentication
• Does not directly support: Supported in Equinox (via Reflection)
getNamedDispatcher
getResourcePaths Set getResourcePaths(String path)
getInitParameters (*)
“Context Path” (*)
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

11. Servlets and Filters
What’s missing… (*) = Workarounds Available:
• Filter (*) • Technique is to wrap-and-adapt your
Servlet or Resource.
• HttpSessionListener Servlet wrapped = new
ContextListenerServletAdaptor(
• HttpSessionAttributeListener myServlet, myListener);
• HttpSessionActivationListener registerServlet(“/myPath”, wrapped,
params, myHttpContext);
• ServletContextListener (*) • See
org.eclipse.equinox.http.helper[s]
• ServletContextAttributeListener
in the Equinox-Incubator CVS
• ServletRequestListener
• not currently API but supported
• ServletRequestAttributeListener
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

12. Dynamic Registration
Two main techniques:
• Code-based
Lifecycle: tied to Bundle START and STOP
More Complex but provides greater control
• Extension Registry (org.eclipse.equinox.http.registry)
Lifecycle: tied to Bundle RESOLVED and UNRESOLVED
Simpler in most cases
• Declarative Services / Spring
URL Space is also dynamic and shared across all registrations
No more than one registration per “alias”
Worth planning – useful techniques with relative URLs
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

13. JSP Support
• Provided by:
org.eclipse.equinox.jsp.jasper.JspServlet
<< public JspServlet(Bundle bundle, String bundleResourcePath, String alias) >>
• No default constructor
• Requires compilation / runtime context from “bundle”
• JSP lookup consistent with OSGi HttpService resource
registration.
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

14. JSP Support – Extension Registry
• Extension Registry Support provided by:
org.eclipse.equinox.jsp.jasper.registry.JspFactory
• ExecutableExtensionFactory
<!--* © Copyright 2007 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corp.; All rights reserved. This source code
is made available under the terms of the Eclipse Public License, v1.0. -->
<extension
point=quot;org.eclipse.equinox.http.registry.servletsquot;>
<servlet
alias=quot;/myPath/*.jsp“
class=quot;org.eclipse.equinox.jsp.jasper.registry.JSPFactory:/bundlePathquot;>
</servlet>
</extension>
• Use “{path}/*.jsp” style alias for JSPs.
Allows a “{path}” resource registration to support more efficiently serving
static resources without an alias namespace collision.
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

15. Exercises
• Start Eclipse & configure target platform
• Hello Servlet
• Hello JSP
• Hello Servlet Registry
• Hello JSP Registry
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
15 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

16. Overview
• Introduction to Server-Side Eclipse
• Developing Server-Side Eclipse applications
• Deploying Server-Side Eclipse applications
• Monitoring and Debugging Server-Side Eclipse
applications
• Summary
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
16 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

17. Recommended deployment scenarios
Deployment depends on target infrastructure:
• Standalone Equinox server application
Embedded HttpService
Lightweight solution – good choice for development
Distribute like Eclipse RCP application
• Run application in External Application Server
Recommended as production solution
Deploy as standard WAR application (scripts provided)
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
17 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

18. Equinox embedding an HttpService
• Run Equinox as standalone application
• Multiple processes isolated
• Embedded HttpService (e.g. Jetty)
• Application functionality based on bundles, Servlets, JSPs, ...
• Add web services as bundle
• Server management based on bundles
Source: Jeff McAffer, Eclipse Summit Europe, Server-Side Symposium, Oct 12nd 2006
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
18 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

19. Deploying standalone Equinox server
• Choose target platform
• Add platform specific launchers if required
• Add common services and bundles (see Eclipse Orbit!)
• Add application plug-ins
• Group bundles / plug-ins as features
Application plug-ins
... ...
Servlet JSP Bundles
Common services
Launcher
commons- Update
Jetty Jasper 3rdParty
(see Orbit)
logging, ... Configurator
Equinox Server-Side Eclipse
Operating System
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
19 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

20. Deploying Standalone Equinox server
• Deploy like an RCP application
Plugins / Feature / Product based export
You have to include SSE related plugins
Maintain config.ini for starting bundles
• Important config.ini settings:
# start an OSGi console
osgi.console=true
# do NOT shutdown OSGi
osgi.noShutdown=true
# do NOT start an Eclipse application
eclipse.ignoreApp=true
• Or use commandline arguments when using Eclipse starter:
# enable OSGi console
-console
# same as osgi.noShutdown=true
-noExit
# start application with <id>
-application <id>
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
20 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

21. Deploy Standard Equinox – Running the Server
• Start Equinox server
java –Dorg.osgi.service.http.port=8080
–jar pluginsorg.eclipse.equinox.launcher_<version>.jar
–console -noExit
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
21 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

22. Application Server running an embedded Equinox
• Launch Equinox in traditional application server
• Isolation between multiple web applications/Equinox instances
• Forwarding (Lite) HttpService exposes application server
capabilities
• Application functionality based on bundles, Servlets, JSPs, ...
• Bridging aspect is referred to as the Servletbridge
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
22 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

23. What is the Servletbridge?
… a bridge between the servlet and OSGi world
Servlet - side OSGi - side
• Eclipse framework launcher • Proxy Servlet that registers with
Bridge Servlet
• Bridge Servlet with a call-back
registration point • OSGi HttpService
1 5
Bridge Servlet Proxy Servlet
Servlet OSGi
2 4
3
Framework Launcher HttpService
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
23 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

24. What is the Servletbridge?
Servlet OSGi
Incoming Request Registered Request Handler
Servletbridge
OSGi HttpService
registerResource(…)
registerServlet(…)
Incoming requests are “proxied” through the
Servletbridge to registered request handlers.
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
24 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

25. Deploying Equinox Inside an Application Server
• Deploy similar to an RCP application but in a Web Archive
/WEB-INF
/web.xml (with one servlet entry assigning all incoming requests to the BridgeServlet)
/lib/servletbridge.jar (the classes associated with the equinox.servletbridge)
/eclipse (the eclipse platform directory)
launch.ini (contains framework properties that will allow override of any eclipse specific
System Properties)
/configuration (contains config.ini which lists the bundles you want to have available at
startup)
/features
/plugins
• org.eclipse.equinox.servletbridge Project
/scripts/webappBuilder.xml (Ant Script for building WAR file)
/templates (contains the WAR directory structure)
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
25 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

26. Deploying Equinox inside Application Server
• Online Demo
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
26 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

27. Exercises
• Create feature for build/export
• Export standalone server using product export
• Create & deploy WAR file using Servlet bridge
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
27 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

28. Overview
• Introduction to Server-Side Eclipse
• Developing Server-Side Eclipse applications
• Deploying Server-Side Eclipse applications
• Monitoring and Debugging Server-Side Eclipse
applications
• Summary
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
28 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

29. Logging in Equinox Jetty 6 Integration
• Jetty logging now controllable in 3.5
• -Dorg.eclipse.equinox.http.jetty.log.stderr.threshold=<level>
quot;debugquot;, quot;infoquot;, quot;warnquot;, quot;errorquot;, and quot;off“
Default is “warn”
• Log will happen to STDERR only (for now)
• Outlook: deeper integration with Extended Equinox
Log Service (3.6)
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
29 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

30. Debugging: Where to hook in
• Hook either in
OSGi world
ServetBridge
• Startup problems:
FrameworkLauncher
• Central access:
ProxyServlet
Hook in processAlias
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
30 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

31. Servlet Bridge Management Commands
“web.xml” allows configuration of initial parameters:
• commandline Allows all non-VM command line parameterizations of Eclipse.
The default value is quot;-console“ which should be cleared for production.
• enableFrameworkControls (true / false) - Controls whether or not the sp_* control URLs are
accessible
sp_deploy - Copies the contents of /platform to the install area (the servlet context tempdir is used -
parameterizable someday)
sp_undeploy - Removes the copy of Eclipse from the install area
sp_redeploy - Resets the platform (e.g. stops, undeploys, deploys, starts)
sp_start - Starts a deployed platform
sp_stop - Stops the platform
sp_test - Provides a sanity check and determines if an OSGi based servlet is ready to accept requests
• frameworkLauncherClass – allows customization of the launcher
• extendedFrameworkExports – additional java package exports from the web application.
Servlet API is automatically exported.
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
31 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

32. Knopflerfish HTTP Console
• Provides convenient way to manage bundles at
runtime
• Works within Servlet Bridge
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
32 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

33. Overview
• Introduction to Server-Side Eclipse
• Developing Server-Side Eclipse applications
• Deploying Server-Side Eclipse applications
• Monitoring and Debugging Server-Side Eclipse
applications
• Summary
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
33 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

34. Summary - Looking forward...
• Eclipse >3.3 supports building OSGi based web applications for:
Equinox based RCP and headless applications
Equinox embedded in an application server
• Outlook for Eclipse 3.5
Jetty 6
• Jetty joined Eclipse much tigther integration expected
• Outlook for OSGi Spec work
Enterprise Expert Group
Http Service according 2.5 Spec
“WebContainer” alike support, but with OSGi dynamics
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
34 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

35. For more information...
Project hub:
http://www.eclipse.org/equinox/server
Newsgroup:
news://news.eclipse.org/eclipse.technology.equinox
Dev Mailing List:
equinox-dev@eclipse.org
Thank-you
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
35 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license

36. Legal Notices
• Java and all Java-based trademarks are trademarks of Sun
Microsystems, Inc. in the United States, other countries, or both
• Microsoft, Windows, Windows NT, and the Windows logo are trademarks
of Microsoft Corporation in the United States, other countries, or both.
• Linux is a registered trademark of Linus Torvalds in the United States,
other countries, or both.
• Other company, product, or service names may be trademarks or service
marks of others
Building Server-Side Eclipse based web applications | Tutorial
© Copyright 2007, 2008, 2009 Jochen Hiller, Simon Kaegi, Gunnar Wagenknecht, IBM Corporation;
36 Source code in this presentation is made available under the EPL, v1.0, remainder of the presentation is licensed under Creative Commons Att. Nc Nd 2.5 license