Expressions, Interpolate called from code throws NPE

[chris.simons]

We're using Expressions to invoke methods, and we've recently tried to use both Expressions and Interpolate to evaluate EL to a String value through a SFSB.

What we're finding is that we can't; we always receive a NullPointerException, but the stack trace is very unclear.  What is the NPE?  We've tried grabbing Expressions/Interpolator in many ways, including:
- injection
- grabbing Seam's instance of the components
- Interpolator.instance()

No matter what we do, we always receive an NPE.  We're running Seam 2.1.2.

Lastly, we can use #{interpolator.interpolate} inside of JSF, and it works like a charm.  But we can't call it from Java code, period, without a resulting NPE.

Here is a sample.

Interpolator interpolator = (Interpolator) Component.getInstance(Interpolator.class, true);

            try {

       log.debug(interpolator.interpolate("#{messages['validator.noUserSelected']}"));

           }
            catch (Exception e)
            {
                e.printStackTrace();
            }

NOTE: We once had this working on JBoss AS, but not we're using Weblogic 10.3.1.  The truth of the matter is that I don't think this is related, but it could be.  Everything else has been working fine under WebLogic.

Thanks.

[chris.simons]

Just wanted to share the exception that we get....

java.lang.NullPointerException
        at com.bah.englink.authentication.CardAuthManager.authenticateCert(CardAuthManager.java:67)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at com.bea.core.repackaged.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:310)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)

        at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at com.bea.core.repackaged.springframework.jee.spi.MethodInvocationVisitorImpl.visit(MethodInvocationVisitorImpl.java:37)
        at weblogic.ejb.container.injection.EnvironmentInterceptorCallbackImpl.callback(EnvironmentInterceptorCallbackImpl.java:54)
        at com.bea.core.repackaged.springframework.jee.spi.EnvironmentInterceptor.invoke(EnvironmentInterceptor.java:50)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at com.bea.core.repackaged.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)

        at com.bea.core.repackaged.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
        at com.bea.core.repackaged.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at com.bea.core.repackaged.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at $Proxy179.authenticateCert(Unknown Source)
        at com.bah.englink.authentication.CardAuthManager_wwndcw_CardAuthManagerLocalImpl.authenticateCert(CardAuthManager_wwndcw_CardAuthManagerLocal
Impl.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
        at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
        at org.jboss.seam.intercept.ClientSideInterceptor$1.proceed(ClientSideInterceptor.java:76)
        at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
        at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
        at org.jboss.seam.intercept.ClientSideInterceptor.invoke(ClientSideInterceptor.java:54)
        at org.javassist.tmp.java.lang.Object_$$_javassist_seam_6.authenticateCert(Object_$$_javassist_seam_6.java)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:335)
        at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:348)
        at org.jboss.el.parser.AstPropertySuffix.invoke(AstPropertySuffix.java:58)
        at org.jboss.el.parser.AstValue.invoke(AstValue.java:96)
        at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
        at com.sun.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:68)
        at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
        at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
        at javax.faces.component.UICommand.broadcast(UICommand.java:387)
        at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:324)
        at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:299)
        at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:256)
        at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:469)
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82)
        at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
        at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
        at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
        at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
        at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
        at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
        at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
        at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
        at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
        at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
        at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
        at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
        at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
        at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3588)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
        at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2200)
        at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2106)
        at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1428)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)

[samdoyle]

Odd, you can try two alternatives:
1.) Interpolator.instance(). ... which just does return (Interpolator) Component.getInstance(Interpolator.class, ScopeType.APPLICATION); if applicationcontext is active.
2.) Interpolator interpolator = (Interpolator) Component.getInstance("org.jboss.seam.core.interpolator")