superclass has no null constructors but no arguments were given without spring integration

Question

java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
    at net.sf.cglib.proxy.Enhancer.emitConstructors(Enhancer.java:721)
    at net.sf.cglib.proxy.Enhancer.generateClass(Enhancer.java:499)
    at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
    at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
    at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
    at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:285)
    at net.thucydides.core.steps.StepFactory.createProxyStepLibrary(StepFactory.java:155)
    at net.thucydides.core.steps.StepFactory.instantiateNewStepLibraryFor(StepFactory.java:109)
    at net.thucydides.core.steps.StepFactory.instantiateNewStepLibraryFor(StepFactory.java:101)
    at net.thucydides.core.steps.StepFactory.getStepLibraryFor(StepFactory.java:67)
    at net.thucydides.core.steps.StepAnnotations.instantiateAnyUnitiaializedSteps(StepAnnotations.java:50)
    at net.thucydides.core.steps.StepAnnotations.instanciateScenarioStepFields(StepAnnotations.java:41)
    at net.thucydides.core.steps.StepAnnotations.injectScenarioStepsInto(StepAnnotations.java:23)
    at net.thucydides.jbehave.ThucydidesStepFactory.createInstanceOfType(ThucydidesStepFactory.java:80)
    at org.jbehave.core.steps.StepCreator.stepsInstance(StepCreator.java:82)
    at org.jbehave.core.steps.StepCreator$ParameterisedStep.perform(StepCreator.java:550)
    at org.jbehave.core.embedder.StoryRunner$FineSoFar.run(StoryRunner.java:499)
    at org.jbehave.core.embedder.StoryRunner.runStepsWhileKeepingState(StoryRunner.java:479)
    at org.jbehave.core.embedder.StoryRunner.runScenarioSteps(StoryRunner.java:443)
    at org.jbehave.core.embedder.StoryRunner.runCancellable(StoryRunner.java:305)
    at org.jbehave.core.embedder.StoryRunner.run(StoryRunner.java:219)
    at org.jbehave.core.embedder.StoryRunner.run(StoryRunner.java:180)
    at org.jbehave.core.embedder.StoryManager$EnqueuedStory.call(StoryManager.java:229)
    at org.jbehave.core.embedder.StoryManager$EnqueuedStory.call(StoryManager.java:201)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

You have a class that is calling the constructor of his implemented class by using super(), with no arguments in it.

Your super class doesn't have a constructor without any arguments.

Example:

public class Cat implements Animal {
    public Cat() {
        super();
    }
}

public class Animal {
    final String name;
    public Animal(String name) {
        this.name = name;
    }
}

The super() in the Cat class will call a constructor with no arguments of the Animal class. The Animal class doesn't have such a constructor and thus will throw an error like yours.

This can also be caused if you are letting a framework like Spring, try to autowire an object, that doesn't have a no-argument constructor.

Please share the class the is throwing the error.

Answer 2

Im not sure this problem was solved, but i managed to understand my problem:

java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given

with following code:

public class CglibTest {
    @Test
    public void shouldCreateDynamicProxy() {
        Enhancer enh = new Enhancer();
        enh.setSuperclass(CgPlay.class);
        enh.setCallback((FixedValue) () -> "fixedValueFromProxy");
        CgPlay cgPlay = (CgPlay) enh.create();
        System.out.println(cgPlay.fooStringPar(null));
    }

    class CgPlay {
        public String fooStringPar(String s) {
            return "fooStringPar";
        }
    }
}

It turned out, the CGLib had problem with CgPlay class, since it was a non-static member inner class. Making CgPlay class a static class, or non-memeber class solved issue.