javac 是Java编译器。 java 是JVM和您用于执行Java程序。你不执行 .java 文件，它们只是源文件。
大概有 .jar 在某处（或一个包含 .class 文件的目录）在Eclipse中构建它：

javac is the Java compiler. java is the JVM and what you use to execute a Java program. You do not execute .java files, they are just source files. Presumably there is .jar somewhere (or a directory containing .class files) that is the product of building it in Eclipse:

java/src/com/mypackage/Main.java
java/classes/com/mypackage/Main.class
java/lib/mypackage.jar

从目录 java execute：

From directory java execute:

java -cp lib / mypackage.jar主要arg1 arg2

java -cp lib/mypackage.jar Main arg1 arg2