我有一个通过logback-classic-1.2.3+logback-core-1.2.3+slf4j-api-1.7.25.jar记录的java项目。它在eclipse中成功运行。但是将项目转换为jar，它有一些问题。以下是错误消息：

Exception in thread "main" java.lang.NoClassDefFoundError: ch/qos/logback/classic/LoggerContext
        at com.wang.log.LogManager.<clinit>(LogManager.java:35)
        at com.wang.startup.StartUp.<clinit>(StartUp.java:10)
Caused by: java.lang.ClassNotFoundException: ch.qos.logback.classic.LoggerContext
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 2 more

I guess the error code is happen in this:
```LoggerContext logbackContext = (LoggerContext) LoggerFactory.getILoggerFactory();```

但我真的不知道为什么，谢谢你的回答。