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Frequently Asked Questions

1. Question: muJava throws a NoClassDefFoundError exception, as shown in the screenshot below:

   Answer: If the exception is thrown right after typing the command "GenMutantsMain" without showing the GUI, it is usually due to corrupted result data in the result folder. You should delete everything in the result folder and try again. (It might work if you just delete the corrupted data, but it's probably simplest to just delete everything.)

   If the GUI shows without problems after typing the command, NoClassDefFoundError is usually because muJava can’t find the class. This is probably because either the classpath is set incorrectly (not pointing to the correct files or folders), or the compiled .class file is not in the class folder.

2. Question: muJava is able to generate mutants, but it cannot kill any of them.

   Answer: First, please make sure that your tests are correct (Now, muJava accepts JUnit tests). Then, please check the setting of your operating system's classpath. If the classes folder of muJava is included in the classpath, please remove it, because it makes muJava load the original class file, instead of the mutants.