org/apache/logging/log4j/util/Base64Util.class: Class Version Error Please recompile with supported JDK

Question

/build/Debug/ant/pdm.jar./META-INF/versions/9/org/apache/logging/log4j/util/Base64Util:class. Class Version Error. Please recompile with a supported JDK or check for an update to DashO which supports the new version.

We are using ant as build tool and Dasho as the code trimming tool.

We are migrating our code from log4j1.x to log4j2.x and we replaced old jar with new Jars(2.xapi & 2.xcore)

Since then after adding the libraries itself we are getting this error while building the project,as we are using java 8 and as per official log4j2 documentation any version of lof4j2 above 2.17.1 does support java8

Found this line when searched for this Base64Util.class in the official documentation of 2.x link Tried using 2.17.1 && 2.15 && 2.13 but no luck

Why this unsupported JDK is coming even after using java8 in project??

Answer 1

In order to support Java 8 and all later releases the log4j-api and log4j-core artifacts are multi-release jars . The class file that gives you problems uses Java 9 bytecode.

According to their web site DashO does not support multi-release jars .

Remark : removing the Java 9 classes from log4j-api and log4j-core will break logger context selection and location information on JDK 9 and later, so it is not an option.