使用包时获取java.lang.ClassNotFoundException [英] Getting java.lang.ClassNotFoundException when using package

问题描述

我有一个带有以下代码的Java文件ComPac.java:

I have a java file ComPac.java with the below code:

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

文件位于路径:/home/ec2-user/java_c

要编译此文件，我运行了javac Compac.java，并生成了类文件.

To compile this file, I ran javac Compac.java, and the class file was generated.

现在该运行类文件了.

所以我做了java ComPac(下面的屏幕截图)

So I did java ComPac(screenshot below)

可以理解，我收到了错误Error: Could not find or load main class ComPac. Caused by: java.lang.NoClassDefFoundError: com/ComPac (wrong name: ComPac). 我假设这是因为java文件中声明了软件包com.

Understandably, I got the error Error: Could not find or load main class ComPac. Caused by: java.lang.NoClassDefFoundError: com/ComPac (wrong name: ComPac). This I am assuming is because the java file has the package com declared in it.

因此，我尝试了java com.ComPac并期望它可以正常工作(下面的屏幕截图).

So instead I tried, java com.ComPac and expected it to work(screenshot below).

但是我得到了错误:Error: Could not find or load main class com.ComPac. Caused by: java.lang.ClassNotFoundException: com.ComPac.

那么我该如何运行呢?在使用Java包时运行的逻辑到底是什么?

So how do I run this? and what exactly is the logic for running when it comes to packages in java?

使用过的Java-openjdk version "11.0.8" 2020-07-14 LTS(AWS Corretto)

使用的操作系统-Amazon Linux 2

推荐答案

将该类放在一个名为"com"的文件夹中.

put the class in a folder called "com"

然后在bash外壳中:

in a bash shell it's then:

$ java com/ComPac

(来自包含"com"的文件夹，而不是"com"内部)

(from the folder containing "com", not inside of "com")

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