Exception in thread “main“ java.lang.NoClassDefFoundError: com/beust/jcommander/ParameterException

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: com/beust/jcommander/ParameterException
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
        at java.lang.Class.privateGetMethodRecursive(Unknown Source)
        at java.lang.Class.getMethod0(Unknown Source)
        at java.lang.Class.getMethod(Unknown Source)
        at sun.launcher.LauncherHelper.validateMainClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.beust.jcommander.ParameterException
        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)
        ... 7 more
最近在用testng 写一个测试框架  最后用命令java org.testng.TestNG testng_user.xml  执行testng.xml 报错了，提示我没有导入jcommander.jar 但是我本地已经导入了，而且我看网上说版本问题，我又换了不同的版本依然报这个错，有哪位大佬知道是什么问题吗？最好给个解决方案，多谢了~