Java在命令提示符下运行程序：找不到或加载主类

D:
 ActivityOne
     - classes
         - com
           -wat
             -sampleapp
                -students
                    StudentE.class
                 StudentMasterList.class (Main)
     - src
         -com
           -wat
             -sampleapp
                -students
                    StudentE.java
                 StudentMasterList.java (Main)

问题是我现在对如何运行程序感到困惑.
我尝试了两件事,两件事都返回了不同的错误.

第一次尝试：

java -classpath classes StudentMasterList

回：

Error: Could not find or load main class StudentMasterList

第二次尝试：

java -classpath classes/com/wat/sampleapp StudentMasterList

回：

Exception in thread "main" java.lang.NoClassDefFoundError: StudentMasterList (wrongname: com/wat/sam
pleapp/StudentMasterList)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

我在下次尝试后感到困惑,对于如何运行主类的任何帮助？

更新：我应该在ActivityOne级别运行所有命令.