java.lang.NoClassDefFoundError: org/springframework/core/annotation/MergedAnnotations$SearchStrategy

最后是修订了spring-test的版本解决了这个问题，将spring-test的版本由5.x降为4.x

java.lang.NoClassDefFoundError: org/springframework/core/annotation/MergedAnnotations$SearchStrategy

	at org.springframework.test.context.support.TestPropertySourceUtils.buildMergedTestPropertySources(TestPropertySourceUtils.java:74)
	at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:386)
	at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildDefaultMergedContextConfiguration(AbstractTestContextBootstrapper.java:312)
	at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:265)
	at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildTestContext(AbstractTestContextBootstrapper.java:108)
	at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.buildTestContext(SpringBootTestContextBootstrapper.java:99)
	at org.springframework.test.context.TestContextManager.(TestContextManager.java:137)
	at org.springframework.test.context.TestContextManager.(TestContextManager.java:122)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTestContextManager(SpringJUnit4ClassRunner.java:151)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.(SpringJUnit4ClassRunner.java:142)
	at org.springframework.test.context.junit4.SpringRunner.(SpringRunner.java:49)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
	at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
	at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
	at org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:36)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:49)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)

public Runner buildRunner(Class runnerClass,
        Class testClass) throws Exception {
    try {
        return runnerClass.getConstructor(Class.class).newInstance(testClass);
    } catch (NoSuchMethodException e) {
        try {
            return runnerClass.getConstructor(Class.class,
                    RunnerBuilder.class).newInstance(testClass, suiteBuilder);
        } catch (NoSuchMethodException e2) {
            String simpleName = runnerClass.getSimpleName();
            throw new InitializationError(String.format(
                    CONSTRUCTOR_ERROR_FORMAT, simpleName, simpleName));
        }
    }
}

runnerClass对象继承了Runner
而runnerClass为SpringRunner类型（spring-test下），springRunner继承了SpringJUnit4ClassRunner，SpringJUnit4ClassRunner继承了BlockJUnit4ClassRunner，BlockJUnit4ClassRunner继承了ParentRunner，ParentRunner继承了Runner

在执行spring-test中的at org.springframework.test.context.support.TestPropertySourceUtils.buildMergedTestPropertySources(TestPropertySourceUtils.java:74)

static MergedTestPropertySources buildMergedTestPropertySources(Class testClass) {
    MergedAnnotations mergedAnnotations = MergedAnnotations.from(testClass, SearchStrategy.TYPE_HIERARCHY);
    return mergedAnnotations.isPresent(TestPropertySource.class) ? mergeTestPropertySources(mergedAnnotations) : MergedTestPropertySources.empty();
}

因为会实例化MergedAnnotations对象，而你的springboot版本过低，不存在java.lang.NoClassDefFoundError: org/springframework/core/annotation/MergedAnnotations$SearchStrategy

所以最好的解决方案降低spring-test的版本，这里我选择降低到4.3.18.RELEASE

 
        org.springframework
        spring-test
        4.3.18.RELEASE