java - 在命令提示符下运行时出现 ClassNotFoundException

Question

我是 java 的新手，尝试运行一个简单的计算体积的代码。代码如下:

package chapter6;

class Box {

    double width;
    double height;
    double depth;
}

---

package chapter6;

    public class BoxDemo {

        public static void main(String[] args) {

            Box myBox = new Box();
            double vol;

            myBox.depth = 1;
            myBox.height = 2;
            myBox.width = 3;

            vol = myBox.depth * myBox.height * myBox.width ;        

            System.out.println("Volume: " + vol);
        }

    }

---

我能够从 eclipse 运行代码，但是当我尝试在命令提示符中运行代码时，出现错误:

C:\Prabhjot\Java\CompleteRefence\build\classes>java BoxDemo.class
Exception in thread "main" java.lang.NoClassDefFoundError: BoxDemo/class
Caused by: java.lang.ClassNotFoundException: BoxDemo.class
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
Could not find the main class: BoxDemo.class.  Program will exit.

请协助。

Answer 1

第一类文件应该在这个位置:

C:\Prabhjot\Java\CompleteRefence\build\classes\chapter6\BoxDemo.class

那么你应该在里面:

C:\Prabhjot\Java\CompleteRefence\build\classes>

然后发出命令:

java chapter6.BoxDemo