如果你说 -cp somejar.jar 你要将 somejar.jar 添加到类路径中。它只会尝试在您输入命令时从您当前所在的目录中找到 somejar.jar 。

If you say -cp somejar.jar you are adding somejar.jar to the classpath. It will only try to find the somejar.jar from the directory you are currently in when you typed the command.

如果你在清单中说

Class-Path: somejar.jar

你是说将jar， somejar.jar 添加到清单所在目录的类路径中找到（也就是在jar中）。

you are saying add the jar, somejar.jar into the classpath from the directory where the manifest is located(aka inside the jar).

作为旁注，当你使用-jar，-cp或-classpath指定类路径时，你会覆盖系统变量CLASSPATH。

As a side note, when you specify the classpath by using -jar, -cp, or -classpath, you override the system variable CLASSPATH.

更多细节可以在这里找到， http://docs.oracle.com/javase/tutorial/deployment/jar/downman.html

More details can be found here, http://docs.oracle.com/javase/tutorial/deployment/jar/downman.html