Normal Steps to Reproduce
display any EL in a zul file:
<zk> ${desktop.id} </zk>
Current Result
org.zkoss.zel.ELException: Unable to find ExpressionFactory of type: # Licensed to the Apache Software Foundation (ASF) under one or more org.zkoss.zel.ExpressionFactory.newInstance(ExpressionFactory.java:167) org.zkoss.zel.ExpressionFactory.newInstance(ExpressionFactory.java:106) org.zkoss.zel.Util.getExpressionFactory(Util.java:126) org.zkoss.zel.ELManager.getExpressionFactory(ELManager.java:30) org.zkoss.zel.ELContext.convertToType(ELContext.java:306) org.zkoss.zel.impl.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) org.zkoss.xel.zel.ELXelExpression.evaluate(ELXelExpression.java:41) org.zkoss.zk.xel.impl.SimpleEvaluator.evaluate(SimpleEvaluator.java:68) org.zkoss.zk.ui.metainfo.AbstractEvalRef.evaluate(AbstractEvalRef.java:46) org.zkoss.zk.xel.ExValue.getValue(ExValue.java:111) org.zkoss.zk.ui.metainfo.Property.getValue(Property.java:138) org.zkoss.zk.ui.metainfo.Property.assign0(Property.java:234) org.zkoss.zk.ui.metainfo.Property.assign(Property.java:174) org.zkoss.zk.ui.metainfo.ComponentInfo.applyProperties(ComponentInfo.java:742) org.zkoss.zk.ui.impl.AbstractUiFactory.newComponent(AbstractUiFactory.java:146) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild0(UiEngineImpl.java:919) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:889) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:776) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:836) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:794) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate(UiEngineImpl.java:740) org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:461) org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:369) org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:211) org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:137) javax.servlet.http.HttpServlet.service(HttpServlet.java:687) javax.servlet.http.HttpServlet.service(HttpServlet.java:790) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) Root Cause java.lang.ClassNotFoundException: # Licensed to the Apache Software Foundation (ASF) under one or more org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1358) org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180) org.zkoss.zel.ExpressionFactory.newInstance(ExpressionFactory.java:160) org.zkoss.zel.ExpressionFactory.newInstance(ExpressionFactory.java:106) org.zkoss.zel.Util.getExpressionFactory(Util.java:126) org.zkoss.zel.ELManager.getExpressionFactory(ELManager.java:30) org.zkoss.zel.ELContext.convertToType(ELContext.java:306) org.zkoss.zel.impl.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) org.zkoss.xel.zel.ELXelExpression.evaluate(ELXelExpression.java:41) org.zkoss.zk.xel.impl.SimpleEvaluator.evaluate(SimpleEvaluator.java:68) org.zkoss.zk.ui.metainfo.AbstractEvalRef.evaluate(AbstractEvalRef.java:46) org.zkoss.zk.xel.ExValue.getValue(ExValue.java:111) org.zkoss.zk.ui.metainfo.Property.getValue(Property.java:138) org.zkoss.zk.ui.metainfo.Property.assign0(Property.java:234) org.zkoss.zk.ui.metainfo.Property.assign(Property.java:174) org.zkoss.zk.ui.metainfo.ComponentInfo.applyProperties(ComponentInfo.java:742) org.zkoss.zk.ui.impl.AbstractUiFactory.newComponent(AbstractUiFactory.java:146) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild0(UiEngineImpl.java:919) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:889) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:776) org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:836) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:794) org.zkoss.zk.ui.impl.UiEngineImpl.execCreate(UiEngineImpl.java:740) org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:461) org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:369) org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:211) org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:137) javax.servlet.http.HttpServlet.service(HttpServlet.java:687) javax.servlet.http.HttpServlet.service(HttpServlet.java:790) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Expected Result
no error
Debug Information
related tomcat issue: https://bz.apache.org/bugzilla/show_bug.cgi?id=64097
in 8.0.5:
The method org.zkoss.zel.ExpressionFactory#getClassNameServices reads the service config file (META-INF/services/javax.el.ExpressionFactory)
and fails to ignore comments after a '#'.
instead it simply returns the first non empty line it finds (in the error case a license comment)
https://github.com/zkoss/zk/blob/v8.0.5/zel/src/org/zkoss/zel/ExpressionFactory.java#L411-L421
Workaround
create a file (e.g. in a standard maven war project)
src/main/resources/META-INF/services/javax.el.ExpressionFactory
with the content:
org.zkoss.zel.impl.ExpressionFactoryImpl
- relates to
-
ZK-3642 ZK can't work with Java unified expression language standard implementation
-
- Closed
-