Multiple issues in Log4J Upgrade for old Java Servlet ( Struts ) based application

Question

Current Situation

Java Application development version: a Struts based GUI application developed in Java 1.5 JDK used for Compilation: 1.7 Tomcat Server: Application is hosted on tomcat 6. Current Log4J version: 2.3 Build Tool: Maven 3

Aim

Upgrade Log4J to latest version.

Problem Description

I have tried multiple ways while upgrading but all various combinations of tomcat and Java. But I am encountering different issues. Below is the list of issues.

**JDK 7, Log4j-2.3 Tomcat 6 ( Current Situation) **

Able to build war file, application gets deployed and runs smoothly.

JDK 7 and Tomcat 6 , Log4j- 2.17.1

The war file generated is not having all the classes from the application. ( Quite surprising ). I enabled the debug logs for maven but did not find any surprising entry. I reverted the Log4j version back to 2.3, and things came back to normal. Tried multiple iterations of this, but still the same issue.

JDK 8 and Tomcat 6 , Log4j- 2.17.1

I am able to build war file successfully ( with all the classes) , and deploy it to tomcat. But when I open the landing page of webapp, I am presented with an error: The type java.io.ObjectInputStream cannot be resolved. It is indirectly referenced from required .class files

On investigating I understood that it is not really a bug with JDK 8 as mentioned in many posts, and it is recommended to upgrade the Tomcat version.

JDK 8 and Tomcat 8 , Log4j- 2.17.1

Successfully able to build war file. While deploying it to Tomcat we get below error:

SEVERE [localhost-startStop-1] org.apache.catalina.startup.ContextConfig.processAnnotationsJar Unable to process Jar entry [xxxxxxxx.class] from Jar [jar:file:/C:/xxxx/xxx/xxxx.war!/WEB-INF/lib/client-1.1.jar] for annotations org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 60

Based on investigation and various posts, we skipped jar scanning for this jar, by adding JarsToSkip in tomcat’s configuration catalina.properties file.

JDK 8 and Tomcat 8 , Log4j- 2.17.1, catalina.properties with jarsToSkip entry for problematic Jar

Able to build war file, and deploy it to Tomcat. Login page opens successfully.

When I submit the login form, application encounters below error: java.lang.NoSuchMethodError: org.apache.catalina.core.StandardContext.findApplicationParameters()[Lorg/apache/catalina/deploy/ApplicationParameter;

Looking at the documentation and code, everything looks fine with method's signature. Quite surprising to have this error.

Tomcat also has catalina.jar, servlet-api.jar files at the right location.

Trying with higher tomcat version.

JDK 8, Tomcat 9, Log4j- 2.17.1, catalina.properties with jarsToSkip entry for problematic Jar

again presented with same error: java.lang.NoSuchMethodError: org.apache.catalina.core.StandardContext.findApplicationParameters()[Lorg/apache/catalina/deploy/ApplicationParameter;

** Tried with Tomcat 10 this time **

Now with this version of tomcat servlet apis are packaged in jakarta.servlet.* package instead of javax.servlet.*

This will need lot of code changes and testing, thus I am avoiding it.

What I am looking for

1. Can you help me understand if the overall process I tried is correct or what should be changed?
2. Which combination of JDK, and Tomcat should I use to be able to use log4J-2.17.1
3. There have been different errors at different combinations, which error should I focus first and try to avoid, to be able to solve this situation.
4. Any suggestions on how this error can be solved.

Please let me know if you need any more details around this, to be able to help.

P.S.:

I am fairly new in Java, Struts, Maven, Tomcat tools, and I may have missed some solutions which may seem basic. I am open for various suggestions.

Thanks.

Answer 1

You should add dependencies for log4j-core and log4j-jc and secondly (in my case) move log4j.properties to log4j2.properties