`java -cp company.HelloWorld`是否可以编译并运行Java应用程序?我猜不是.我只需要再次确认 [英] Does `java -cp company.HelloWorld` compile and run an java application? I guess not. I just need a double confirmation

问题描述

我关注此帖子和此

I following this post and this post to build an java app.

这是我的 company/HelloWorld.java

package company;

public class HelloWorld {
   public static void main(String[] args) {
      System.out.println("Hello, World");
   }
}

通常，运行Java程序需要2个步骤:

Classically, running a java program needs 2 steps:

1. javac文件，例如 javac company/HelloWorld.java
2. java类文件，例如 java company.HelloWorld

正如预期的那样，它给了我世界你好".

which gave me "Hello, World", as expected.

尽管我的环境似乎无法识别此命令，但 java -cp 似乎可以批量完成上述两个步骤

It seems java -cp could do the 2 steps above in a batch, although it seems that my env does not recognize this command

java -cp company.HelloWorld

并输出

用法:java [-options]类[args ...]

Usage: java [-options] class [args...]

根据@hayrettinm的回答，这是另一个版本.

this is another version, according to @hayrettinm's answer.

package company.HelloWorld;

也不起作用.我想念什么?

didn't work either. what am I missing?

为什么我认为 java -cp 可以编译并运行?此

Why do I thought java -cp could do compile and run? this post gives this example

PS C:\Lecture_java\Lecture001\Hello> & 'C:\Users\ubuntu\.vscode\extensions\vscjava.vscode-java-debug-0.23.0\scripts\launcher.bat' 'C:\Program Files\Java\jdk-13.0.1\bin\java' '-Dfile.encoding=UTF-8' '-cp' 'C:\Lecture_java\Lecture001\Hello\bin' 'app.App'

实验结束后，我猜想 java -cp company.HelloWorld 无法编译运行，它只能运行Java应用程序.有人可以给一个再次确认.

after the experiment, I guess java -cp company.HelloWorld could not compile and run, it just run an java application. Could someone give a double confirmation.

推荐答案

java -cp不会执行您编写的内容.

java -cp doesn't do what you write.

javac可执行文件是将您的类编译为字节码的编译器，Java可执行文件基本上是可以理解您已编译的字节码的运行时.

javac executable is the compiler that compiles your class to bytecode, java executable is basically the runtime that understands the bytecode you have compiled.

此外，

如果要使用软件包 com.company.HelloWorld 您必须在您的班级中像这样编写包清理:

If you want to use package com.company.HelloWorld you have to write package decleration like this in your class:

package com.company.HelloWorld;

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