[jira] [Created] (GERONIMO-6482) Ensure loading of JVM ext classloader classes from Geronimo bundles

["Andy McCright (JIRA)" <ji...@apache.org>]

Andy McCright created GERONIMO-6482:
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             Summary: Ensure loading of JVM ext classloader classes from Geronimo bundles
                 Key: GERONIMO-6482
                 URL: https://issues.apache.org/jira/browse/GERONIMO-6482
             Project: Geronimo
          Issue Type: Bug
      Security Level: public (Regular issues)
          Components: osgi
    Affects Versions: 3.0.1
            Reporter: Andy McCright
            Assignee: Andy McCright
            Priority: Minor


IBM has changed the classloader used to load com.sun.* (specifically com.sun.script.javascript) classes in JDK 7.  In JDK 6, these classes were loaded by the JVM's boot classloader - in JDK 7, they are loaded via the JVM's ext classloader (a child classloader of the boot loader).  This change has the effect of breaking servlet code like this:


        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        if(engine == null) {
         throw new RuntimeException("Oh no, unable to find a script engine found for JavaScript");
        }

When running Geronimo 3.0.1 on JDK 6, this code works (engine is non-null, no exception is thrown).  When I switch to JDK7, I see:
ScriptEngineManager providers.next(): javax.script.ScriptEngineFactory: Provider com.sun.script.javascript.RhinoScriptEngineFactory not found
java.lang.RuntimeException: Oh no, unable to find a script engine found for JavaScript
    at org.apache.jsp.HelloWorld_jsp._jspService(HelloWorld_jsp.java:96)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.geronimo.tomcat.GeronimoStandardContext$SystemMethodValve.invoke(GeronimoStandardContext.java:731)
    at org.apache.geronimo.tomcat.valve.GeronimoBeforeAfterValve.invoke(GeronimoBeforeAfterValve.java:48)
    at org.apache.geronimo.tomcat.valve.ProtectedTargetValve.invoke(ProtectedTargetValve.java:53)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:947)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1009)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at org.apache.geronimo.pool.ThreadPool$1.run(ThreadPool.java:267)
    at org.apache.geronimo.pool.ThreadPool$ContextClassLoaderRunnable.run(ThreadPool.java:397)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1121)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:614)
    at java.lang.Thread.run(Thread.java:769)

The reason this fails is that the bundle's classloader's parent loader is the JVM's boot classloader, not the ext loader - so it cannot load the com.sun.* classes that it needs (and that it could in JDK6).

One solution to this is to add the following line to <geronimo_home>/etc/system.properties:
osgi.parentClassloader=ext

This forces the bundle's to search the ext loader (in addition to the boot loader) on boot delegated loads.

Jarek suggested using the following system property, which similarly resovles the problem (by forcing all bundles to use the framework classloader as its parent) and is a property used in Karaf:
org.osgi.framework.bundle.parent=framework


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