Wiki source code of Dysoweb
Last modified by Pierre Dubois on 2011/10/03 21:39
Show last authors
| 1 | A Dysoweb application is at the same time an OSGi bundle and a mini "Web archive" (War) with some specificities (at least for the structure of the Web application) |
| 2 | |
| 3 | == OSGi Bundle == |
| 4 | |
| 5 | An OSGi bundle is usually a Jar file (altough at least Equinox and Felix support bundles as exploded directories) that contains some specific information in the manifest. |
| 6 | |
| 7 | Therefore, a Dysoweb application will get the following from its bundle structure: |
| 8 | |
| 9 | - META-INF/MANIFEST.MF |
| 10 | Contains the Bundle name, symbolic name, and version. |
| 11 | |
| 12 | Activator : A java class that will be called when the application is started (see extensive OSGi litterature on the subject) |
| 13 | The activator must declare a "WebAppService" that will be used by the Dysoweb processor to register the application: |
| 14 | |
| 15 | /* |
| 16 | |
| 17 | * (non-Javadoc) |
| 18 | * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext) |
| 19 | */ |
| 20 | public void start(BundleContext context) throws Exception { |
| 21 | fWebApp = context.registerService(WebAppService.class.getName(), |
| 22 | new WebAppService(context.getBundle()) { }, |
| 23 | null); |
| 24 | } |
| 25 | |
| 26 | /* |
| 27 | |
| 28 | * (non-Javadoc) |
| 29 | * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext) |
| 30 | */ |
| 31 | public void stop(BundleContext context) throws Exception { |
| 32 | // unregister the web app service |
| 33 | fWebApp.unregister(); |
| 34 | fWebApp = null; |
| 35 | }// |
| 36 | |
| 37 | |
| 38 | [[Creating an OSGi bundle>>DevelopOSGIBundle]] |
| 39 | |
| 40 | == Class path == |
| 41 | |
| 42 | This is an important point, since WEB apps and OSGi bundles have a different way of specifiying which classes should be loaded. |
| 43 | |
| 44 | In DysoWeb, the classes and librairies (jar) are loaded according to the OSGi spec, and are '''NOT loaded from WEB-INF/classes or WEB-INF/lib'''. They are loaded from the regular bundle class path (by default .), but it can be specified by the "Bundle-ClassPath" header in the manifest of the bundle. |
| 45 | |
| 46 | == Manifest Example == |
| 47 | |
| 48 | Manifest-Version: 1.0 |
| 49 | Bundle-ManifestVersion: 2 |
| 50 | Bundle-Name: Test Plug-in |
| 51 | Bundle-SymbolicName: com.requea.test |
| 52 | Bundle-Version: 1.0.0 |
| 53 | Bundle-Activator: com.requea.test.Activator |
| 54 | Import-Package: com.requea.dysoweb, |
| 55 | org.osgi.framework;version="1.3.0" |
| 56 | Bundle-ClassPath: bin/, |
| 57 | ., |
| 58 | lib/commons-lang-2.1.jar, |
| 59 | lib/commons-resources.jar |
| 60 | |
| 61 | |
| 62 | == Web App == |
| 63 | |
| 64 | The Web application content (static files, JSP, TLD, WEB-INF/web.xml) are put in the webapp directory in the bundle: |
| 65 | |
| 66 | Therefore, the structure of a Dysoweb app looks like: |
| 67 | |
| 68 | [[image:DysowebApp.png]] |
| 69 | |
| 70 | == web.xml == |
| 71 | |
| 72 | The web.xml defined in webapp/WEB-INF/web.xml has a typical servlet application structure. You can define servlets, servlets mappings, filter and filter mappings. |
| 73 | |
| 74 | <?xml version="1.0" encoding="ISO-8859-1"?> |
| 75 | <web-app> |
| 76 | <display-name>Demo4 WebApp</display-name> |
| 77 | <servlet> |
| 78 | <servlet-name>voteServlet</servlet-name> |
| 79 | <servlet-class>com.requea.dysoweb.demo4.VoteServlet</servlet-class> |
| 80 | <load-on-startup>1</load-on-startup> |
| 81 | </servlet> |
| 82 | <servlet-mapping> |
| 83 | <servlet-name>voteServlet</servlet-name> |
| 84 | <url-pattern>/demo4/vote</url-pattern> |
| 85 | </servlet-mapping> |
| 86 | </web-app> |