link GetOpt to main jar

I have a folder gnu\getopt contains Getopt.class which is need by ChatDemo.jar for parser argument parameters, when I ran with java -cp xSocket.jar;. ChatDemo.jar it produce:

Exception in thread "main" java.lang.NoClassDefFoundError: gnu/getopt/Getopt
        at ChatDemo.main(ChatDemo.java:24)
Caused by: java.lang.ClassNotFoundException: gnu.getopt.Getopt
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
 开发者_如何学Python       at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        ... 1 more

ChatDemo.java:

import gnu.getopt.Getopt;

ChatDemo Manifest:

Manifest-Version: 1.0
Created-By: 1.6.0_22 (Sun Microsystems Inc.)
Main-Class: ChatDemo
Class-Path: xSocket.jar

Run it with java -classpath "xSocket.jar;.;ChatDemo.jar ChatDemo (no .jar after the name of the main class).

Note that you must add the folder which contains "gnu" to the classpath. Another solution is to put the getopt classes in a JAR and add that to the classpath. Make sure that the folder structure (gnu\getopt) is preserved.

It looks like you are mixing up the two ways of running java. You should either supply a classpath (e.g. using the -cp argument), or launch from a JAR file. You cannot do both.

If you launch using a JAR file, the -cp argument is ignored. In that case, you must specify the complete classpath in the JAR file's manifest.

The manifest in the ChatDemo.jar file apparently doesn't include. You can remedy this in two ways:

• Update the manifest classpath to be "Class-path: xSocket.jar ." ... note we use a space to separate the entries here, not ; or :.
• Add Getopt.class to the JAR file as gnu/getopt/Getopt.class.

However, if you launch using a JAR file you have to use the -jar option. If you try to your application like this:

    java -cp xSocket.jar;. ChatDemo.jar

it will fail telling you that it cannot find a class called ChatDemo.jar ; i.e. it will misinterpret the JAR filename as a qualified classname.

Add Main-Class - as fully qualified (I mean as per package structure) class name of your class which contains main method.