环境
IDEA 2019.3
OS：macOS 15
在 test 目录下执行单元测试时报错
java.lang.NoClassDefFoundError: org/junit/platform/launcher/core/LauncherFactory at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.<init>(JUnit5TestLoader.java:31) 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:408) at java.lang.Class.newInstance(Class.java:438) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createRawTestLoader(RemoteTestRunner.java:367) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.createLoader(RemoteTestRunner.java:362) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.defaultInit(RemoteTestRunner.java:306) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.init(RemoteTestRunner.java:221) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:205) Caused by: java.lang.ClassNotFoundException: org.junit.platform.launcher.core.LauncherFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:372) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:360) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 11 more
添加 junit-platform-launcher 依赖即可。
<dependency> <groupId>org.junit.platform</groupId> <artifactId>junit-platform-launcher</artifactId> </dependency>
原因
因为 JUnit 5 = JUnit Platform + JUnit Jupiter + JUnit Vintage
- JUnit Platform是提供了运行（测试框架）环境的平台
- Unit Jupiter 是新的Junit5（子项目提供了一个基于平台测试运行Jupiter的测试引擎）
- JUnit Vintage提供了Junit3/4的测试引擎（向前兼容）
所以这里报错的原因应该是：缺少对应依赖（）。
