报错信息
org.junit.runners.model.InvalidTestClassError: Invalid test class 'com.ifjanuary.demo.test.DemoTest': 1. No runnable methods at org.junit.runners.ParentRunner.validate(ParentRunner.java:525) at org.junit.runners.ParentRunner.<init>(ParentRunner.java:92) at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:74) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:137) at org.springframework.test.context.junit4.SpringRunner.<init>(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.vintage.engine.discovery.DefensiveAllDefaultPossibilitiesBuilder$DefensiveAnnotatedBuilder.buildRunner(DefensiveAllDefaultPossibilitiesBuilder.java:114) at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:70) at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:37) at org.junit.vintage.engine.discovery.DefensiveAllDefaultPossibilitiesBuilder.runnerForClass(DefensiveAllDefaultPossibilitiesBuilder.java:57) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:70) at org.junit.vintage.engine.discovery.ClassSelectorResolver.resolveTestClass(ClassSelectorResolver.java:66) at org.junit.vintage.engine.discovery.ClassSelectorResolver.resolve(ClassSelectorResolver.java:47) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.lambda$resolve$2(EngineDiscoveryRequestResolution.java:134) at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) at java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1361) at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126) at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:499) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:486) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:185) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:125) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.access$100(EngineDiscoveryRequestResolution.java:57) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution$DefaultContext.resolve(EngineDiscoveryRequestResolution.java:224) at org.junit.vintage.engine.discovery.MethodSelectorResolver.resolveParentAndAddFilter(MethodSelectorResolver.java:55) at org.junit.vintage.engine.discovery.MethodSelectorResolver.resolve(MethodSelectorResolver.java:39) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.lambda$resolve$2(EngineDiscoveryRequestResolution.java:146) at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) at java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1361) at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126) at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:499) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:486) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:185) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolve(EngineDiscoveryRequestResolution.java:125) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:91) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:82) at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolver.resolve(EngineDiscoveryRequestResolver.java:113) at org.junit.vintage.engine.discovery.VintageDiscoverer.discover(VintageDiscoverer.java:44) at org.junit.vintage.engine.VintageTestEngine.discover(VintageTestEngine.java:63) at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:103) at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:85) at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:92) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75) at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
原因：导错包
错误包
import org.junit.jupiter.api.Test
正确包
import org.junit.Test;
之后就能正确运行啦