Class LibExtClassLoaderHelper

java.lang.Object
org.eclipse.jetty.osgi.LibExtClassLoaderHelper

public class LibExtClassLoaderHelper extends Object
LibExtClassLoaderHelper

Helper to create a URL class-loader with the jars inside ${jetty.home}/lib/ext and ${jetty.home}/resources. In an ideal world, every library is an OSGi bundle that does loads nicely. To support standard jars or bundles that cannot be loaded in the current OSGi environment, we support inserting the jars in the usual jetty/lib/ext folders in the proper classpath for the webapps.

The drawback is that those jars will not be available in the OSGi classloader.

Alternatives to placing jars in lib/ext:

  1. Bundle the jars in an osgi bundle. Have the webapp(s) that need these jars depend on that bundle.
  2. Bundle those jars in an osgi bundle-fragment that targets the jetty-bootstrap bundle
  3. Use equinox Buddy-Policy: register a buddy of the jetty bootstrapper bundle. (Note: it will work only on equinox)
  • Field Details

  • Constructor Details

    • LibExtClassLoaderHelper

      public LibExtClassLoaderHelper()
  • Method Details

    • createLibEtcClassLoader

      public static ClassLoader createLibEtcClassLoader(File jettyHome, ClassLoader parentClassLoader) throws MalformedURLException
      Parameters:
      jettyHome - the jetty home
      parentClassLoader - the parent classloader
      Returns:
      a url classloader with the jars of resources, lib/ext and the jars passed in the other argument. The parent classloader usually is the JettyBootStrapper (an osgi classloader.
      Throws:
      MalformedURLException - if the jetty home reference is invalid
    • createLibExtClassLoader

      public static ClassLoader createLibExtClassLoader(List<File> jarsContainerOrJars, List<URL> otherJarsOrFolder, ClassLoader parentClassLoader) throws MalformedURLException
      Parameters:
      jarsContainerOrJars - the jars via file references
      otherJarsOrFolder - more jars via url references
      parentClassLoader - the parent classloader
      Returns:
      a url classloader with the jars of resources, lib/ext and the jars passed in the other argument. The parent classloader usually is the JettyBootStrapper (an osgi classloader). If there was no extra jars to insert, then just return the parentClassLoader.
      Throws:
      MalformedURLException - if there is a bad jar file reference
    • processFilesInResourcesFolder

      protected static void processFilesInResourcesFolder(File jettyHome, Map<String,File> childrenFiles)
      When we find files typically used for central logging configuration we do what it takes in this method to do what the user expects. Without depending too much directly on a particular logging framework.

      We can afford to do some implementation specific code for a logging framework only in a fragment.

      Trying to configure log4j and logback in here.

      We recommend that slf4j jars are all placed in the osgi framework. And a single implementation if possible packaged as an osgi bundle is there.

      Parameters:
      jettyHome - the jetty home reference
      childrenFiles - the map of child files