java - 简单网络程序中的 noclassdefounderror。我正在使用 Eclipse IDE 来运行 java 程序

Question

import java.net.InetAddress;
import java.net.UnknownHostException;

class IpAddr {
    public static void main(String arg[]) {
        System.out.println("Hello Jagadeesh...>!!");
        try {
            InetAddress ia=InetAddress.getByName("www.facebook.com");
            System.out.println(ia);
        }
        catch(UnknownHostException uhe) {
            System.out.println("ip address of facebook is not found. :(");
        }
    }
}

在控制台中:运行时 E:\myworkspace\network_practice\src\stage1>javac IpAddr.java E:\myworkspace\network_practice\src\stage1>java IpAddr

线程“main”中的异常 java.lang.NoClassDefFoundError: IpAddr(错误名称:s tage1/IpAddr)

at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

E:\myworkspace\network_practice\src\stage1>cd..

Answer 1

你没有在你的类中声明一个包，所以它进入默认包。但是你有 stage1 文件夹。