在spring boot下junit的使用導報錯誤，可能有下面錯誤
Connected to the target VM, address: '127.0.0.1:56019', transport: 'socket'
四月 03, 2018 9:56:42 上午 org.junit.vintage.engine.discovery.TestClassRequestResolver determineRunnerTestDescriptor
警告: Runner org.junit.internal.runners.ErrorReportingRunner (used on com.test.MapperTest) does not support filtering and will therefore be run completely.
四月 03, 2018 9:56:42 上午 org.junit.vintage.engine.discovery.TestClassRequestResolver determineRunnerTestDescriptor
警告: Runner org.junit.internal.runners.ErrorReportingRunner (used on com.test.MapperTest) does not support filtering and will therefore be run completely.
null
Disconnected from the target VM, address: '127.0.0.1:56019', transport: 'socket'
java.lang.Exception: No runnable methods
at org.junit.runners.BlockJUnit4ClassRunner.validateInstanceMethods(BlockJUnit4ClassRunner.java:191)
at org.junit.runners.BlockJUnit4ClassRunner.collectInitializationErrors(BlockJUnit4ClassRunner.java:128)
at org.junit.runners.ParentRunner.validate(ParentRunner.java:416)
at org.junit.runners.ParentRunner.<init>(ParentRunner.java:84)
at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:65)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:137)
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$DefensiveAnnotatedBuilder.buildRunner(DefensiveAllDefaultPossibilitiesBuilder.java:113)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.vintage.engine.discovery.DefensiveAllDefaultPossibilitiesBuilder.runnerForClass(DefensiveAllDefaultPossibilitiesBuilder.java:56)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.vintage.engine.discovery.TestClassRequestResolver.createRunnerTestDescriptor(TestClassRequestResolver.java:55)
at org.junit.vintage.engine.discovery.VintageDiscoverer.lambda$discover$0(VintageDiscoverer.java:53)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:743)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.vintage.engine.discovery.VintageDiscoverer.discover(VintageDiscoverer.java:55)
at org.junit.vintage.engine.VintageTestEngine.discover(VintageTestEngine.java:61)
at org.junit.platform.launcher.core.DefaultLauncher.discoverEngineRoot(DefaultLauncher.java:130)
at org.junit.platform.launcher.core.DefaultLauncher.discoverRoot(DefaultLauncher.java:117)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:65)
at com.intellij.rt.execution.junit.IdeaTestRunner$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)
Process finished with exit code 255
這個是報錯
原因：
junit版本對應錯誤 你在pom里的junit和@Test的junit版本不一致 在@Test時選擇maven下的版本就可以了，不要選帶api的，還有SpringJUnit4ClassRunner只支持4.12版本及以上。
解決方法：
將org.junit.jupiter.api.Test;這個包替換成org.junit.Test;