打造一个基于OSGi的Web Application——使用Tomcat原生API来动态管理Web元素：原理

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />-->1 <?xml version="1.0" encoding="UTF-8"?>

2<Contextprivileged="true"/>

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />--> 1 package org.dbstar.osgi.web.launcher.tomcat;

2

3importjava.util.Properties;

4

5importjavax.servlet.ServletException;

6importjavax.servlet.UnavailableException;

7importjavax.servlet.http.HttpServlet;

8

9importorg.apache.catalina.ContainerServlet;

10importorg.apache.catalina.Context;

11importorg.apache.catalina.Wrapper;

12importorg.dbstar.osgi.web.launcher.FrameworkConfigListener;

13importorg.osgi.framework.BundleContext;

14importorg.osgi.framework.ServiceRegistration;

15importorg.osgi.framework.launch.Framework;

16

17publicfinalclassTomcatContextServletextendsHttpServletimplementsContainerServlet{

18privatestaticfinallongserialVersionUID=-3977062987005392657L;

19

20privateWrapperwrapper;

21privateContextcontext;

22

23privateServiceRegistrationregistration;

24

25publicWrappergetWrapper(){

26returnwrapper;

27}

28

29publicvoidsetWrapper(Wrapperwrapper){

30this.wrapper=wrapper;

31if(wrapper==null)context=null;

32elsecontext=(Context)wrapper.getParent();

33}

34

35@Override

36publicvoidinit()throwsServletException{

37//EnsurethatourContainerServletpropertieshavebeenset

38if((wrapper==null)||(context==null))thrownewUnavailableException("Wrappernotset.");

39

40//EnsurethatFrameworkhavebeenset

41Frameworkframework=FrameworkConfigListener.getFramework();

42if(framework==null)thrownewUnavailableException("Frameworknotset.");

43

44//将context注册为服务

45registration=registerContext(framework.getBundleContext(),context);

46}

47

48privatestaticServiceRegistrationregisterContext(BundleContextbundleContext,Contextcontext){

49Propertiesproperties=newProperties();

50properties.setProperty("DisplayName",context.getDisplayName());

51properties.setProperty("ContextPath",context.getPath());

52returnbundleContext.registerService(Context.class.getName(),context,properties);

53}

54

55@Override

56publicvoiddestroy(){

57if(registration==null)return;

58

59Frameworkframework=FrameworkConfigListener.getFramework();

60if(framework==null)return;

61

62if(framework.getState()==Framework.ACTIVE)registration.unregister();

63registration=null;

64}

65 }

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />-->1     <!-- register a org.apache.catalina.Context to OSGi Container    -->

2<servlet>

3<servlet-name>TomcatContextServlet</servlet-name>

4<servlet-class>org.dbstar.osgi.web.launcher.tomcat.TomcatContextServlet</servlet-class>

5<load-on-startup>1</load-on-startup>

6     </servlet>

<!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />--> 1 Manifest-Version: 1.0

2Bundle-ManifestVersion:2

3Bundle-Name:CatalinaExtensionFragment

4Bundle-SymbolicName:org.apache.catalina_extension;singleton:=true

5Bundle-Version:5.5.28

6Bundle-Vendor:dbstar

7Fragment-Host:system.bundle;extension:=framework

8Bundle-RequiredExecutionEnvironment:J2SE-1.5

9Export-Package:org.apache.catalina,org.apache.catalina.authenticator,

10org.apache.catalina.connector,org.apache.catalina.core,org.apache.cat

11alina.deploy,org.apache.catalina.loader,org.apache.catalina.mbeans,or

12g.apache.catalina.realm,org.apache.catalina.security,org.apache.catal

13ina.session,org.apache.catalina.startup,org.apache.catalina.users,org

14.apache.catalina.util,org.apache.catalina.valves