-6 
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)
4

2 回答 2

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.

于 2020-06-11T10:11:58.270 回答
0

你有一个类通过使用 super() 调用他实现的类的构造函数，其中没有参数。

您的超类没有没有任何参数的构造函数。

例子：

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

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

Cat 类中的super()将调用 Animal 类的不带参数的构造函数。Animal 类没有这样的构造函数，因此会抛出像你这样的错误。

如果您让像 Spring 这样的框架尝试自动装配一个没有无参数构造函数的对象，也可能会导致这种情况。

请分享抛出错误的课程。

于 2017-12-08T13:51:15.220 回答