'java.lang.NoClassDefFoundError on Docker

When The Program is Ran in the Local PC, it is working fine, but if it is running in the docker throws the following error:

Exception in thread "Thread-16" java.lang.NoClassDefFoundError: org/apache/kafka/common/serialization/Serializer
    at org.eclipse.kura.example.configurable.ConfigurableExample$1.run(ConfigurableExample.java:52)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.apache.kafka.common.serialization.Serializer cannot be found by org.eclipse.kura.example.configurable_1.0.0.202201251713
    at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:484)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:395)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:387)
    at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:150)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    ... 2 more

But this is working fine in the LocalMachine. What is the issue ?

javaapache-kafka


Solution 1:[1]

This may be debugged in following ways:

  1. Ensure that you have all the required dependencies inside your docker container. You may want to check your docker base image first.
  2. Check if you have set the classpath appropriately to include that jar file (kafka-clients).
  3. Validate your entrypoint/cmd which you use to start the service to check if it has the appropriate classpath.
  4. Check your classloader and see why it is not able to load that class.
  5. If your executable is a fat jar file, check if that jar file contains the kafka-clients library where that class is present.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 JavaTechnical

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