How can I solve "java.lang.NoClassDefFoundError"?

java.lang.NoClassDefFoundError is an error that occurs when the Java Virtual Machine (JVM) can't find a required class definition at runtime. This can happen for a variety of reasons, including:

  1. The class is not in the classpath: Make sure that the class you are trying to use is in the classpath and can be found by the JVM.

  2. The class was compiled with a different version of the JDK: Make sure that you are using the correct version of the JDK to run the program.

  3. A dependency is missing: Make sure that all required dependencies are included in the classpath.

  4. The class has been modified or deleted: If you have recently modified or deleted the class, make sure that you have saved and compiled the changes and that the new class file is in the classpath.

  5. There is a problem with the class file: There could be a problem with the class file itself, such as corruption or a compile-time error. In this case, you will need to fix the problem and recompile the class.

I hope this helps! Let me know if you have any other questions.