On 2/7/22 14:50, Robert Turner wrote:
All
I'm hoping that someone can point me in the right direction as this issue
has been baffling me all day, and I'm starting to run out of ideas of what
to look at next.
The logic below is working without issue until I move our test environment
into a Docker container. I'm using the same Tomcat version, and the same
JDK in both the container and the non-container environments.
I've got some EL in a JSP page, for example (simplified):
<p>${class1.field}</p>
And an attribute is set on the page context as follows:
final package1.Class1 objectValue = ...; // either value object of Class1
or null
pageContext.setAttribute("class1", objectValue);
Now, when objectValue is pointing to a valid object, everything is okay.
But when objectValue is null, this is where things get peculiar (and I get
both a working and non-working behaviour in the different environments).
I can easily work around the issue by changing the EL to:
<p>${not empty class1 ? class1.field : ''$}</p>
But it is my understanding that EL should handle nulls on it's own, and
this shouldn't be necessary.
In the failure situation in the docker container, I'm seeing a
NoClassDefFoundError exception for "package1/Class1" below [1] during the
JSP page "rendering". Things work fine outside the docker container.
It might be worth noting that in my case, the attribute name is of the same
name as the actual class (with the first letter being lowercase for the
attribute instead of uppercase in the class).
Note that I've also replaced my actual package name and class names with
"package1" and "Class1", and the attribute name with "class", but they
translate 1-to-1 as in what I've provided here and do not use reserved
names.
I've done a bit of digging into the EL scope resolution code in Tomcat, and
I'm suspecting it might be related to how it chooses the scope of the
object. Possibly related to maybe looking for static aspects of the class,
or something like that. After reviewing the Servlet / JSP / EL
documentation, I also haven't found anything obvious that would suggest
what the problem might be.
Hopefully someone has encountered this before and can nudge me in the right
direction.
Thanks in advance,
Robert
[1]
Caused by: java.lang.NoClassDefFoundError: package1/Class1 (wrong name:
package1/class1)
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
at
java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
at
org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2478)
at
org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:870)
at
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1371)
at
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1215)
at javax.el.ImportHandler.findClass(ImportHandler.java:477)
at javax.el.ImportHandler.resolveClass(ImportHandler.java:421)
at
javax.servlet.jsp.el.ScopedAttributeELResolver.getValue(ScopedAttributeELResolver.java:85)
at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:124)
at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:93)
at org.apache.el.parser.AstValue.getValue(AstValue.java:136)
at org.apache.el.parser.AstFunction.getValue(AstFunction.java:188)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
at
org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:692)
at
And you're sure package1 is on the classpath of the docker version?
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