将OSGI嵌入战争中

Question

我有兴趣在我的WAR中添加一个OSGI容器,但我找不到有关如何执行此操作的教程或文档.我找到了一些根本没用的东西.我对Felix实现和Atlassian实现很感兴趣.

我愿意这样做,以便我的战争接受插件,我可以动态扩展我的Web应用程序,并将其部署到任何Web服务器.

任何指向文档的链接？任何帮助表示赞赏.

Answer 1

将OSGi Framework启动程序添加到Web应用程序并不是什么大问题.

您需要添加一个侦听器以在web.xml中启动框架启动程序

<listener>
  <listener-class>at.badgateway.StartupListener</listener-class>
</listener>

startuplistener看起来像这样

public class StartupListener implements ServletContextListener {

//vars

    @Override
    public void contextInitialized(ServletContextEvent event) {
        // set props
    Map<String, String> config = new HashMap<String, String>();
    config.put(Constants.FRAMEWORK_STORAGE, "path to cache");
    config.put(Constants.FRAMEWORK_STORAGE_CLEAN, "true");

        try {
                    // get framework and start it
            FrameworkFactory frameworkFactory = ServiceLoader.load(FrameworkFactory.class).iterator().next();
            framework = frameworkFactory.newFramework(config);
            framework.start();

                    // start existing bundles
            bundleContext = framework.getBundleContext();
            starter = new MyBundleStarter(servletContext, bundleContext);
            starter.launch();

        } catch (Exception ex)  
    }

    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
         // stop framework
    }
}

在上面的引文中处理MyBundlestarter类,它是激活战争中包含的所有包的类.(例如/ WEB-INF/Osgi-Bundles)

import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
public class MyBundleStarter{

    private BundleContext bundleContext = null;

    public void launch() throws Exception {

        ArrayList<Bundle> availableBundles= new ArrayList<Bundle>();
        //get and open available bundles
        for (URL url : getBundlesInWar()) {
            Bundle bundle = bundleContext.installBundle(url.getFile(), url.openStream());
            availableBundles.add(bundle);
        }

        //start the bundles
        for (Bundle bundle : availableBundles) {
            try{
            bundle.start();
            }catch()
        }

    private List<URL> getBundlesInWar() throws Exception {
        // returns a list of URLs located at destination
    }
}

最后但同样重要的是,您必须为项目添加一个osgi框架.

    <dependency>
    <groupId>org.apache.felix</groupId>
    <artifactId>org.apache.felix.framework</artifactId>
    </dependency>

要么

    <dependency>
        <groupId>org.eclipse.osgi</groupId>
        <artifactId>org.eclipse.osgi</artifactId>
    </dependency>