A friend of mine wanted to start to learn java, and I wanted to help him, so we created a simple Hello World example.
public class Hello {
public static void main(String argv[]) {
system.out.println("Hello world !");
}
}
then, when you compile it: > javac Hello.java and want to execute it: > java Hello
Exception in thread "main" java.lang.NoClassDefFoundError: Hello
We set the CLASSPATH and JAVA_HOME enviroment variable correctly, and the problem was still the same..
When we copied the Hello.class into a lib directory of JAVA_HOME, it worked, but not from the current directory ! We tried different versions of java.. and do you know where this stupid problem is? in the CLASSPATH there should be: CLASSPATH=.;c:/programme/jboss/lib;c:/programme/ j2sdk1.4.2_08/lib;c:/programme/j2sdk1.4.2_08/jre/lib; ... yes.. a dot .. it means, that it will search for classes bytecode in the current directory ! you can also tell java to search the current directory with the -classpath parameter > java -classpath . Hello Problems like this can really discourage java newbies, and that moment was very embarassing :)
我的解决方法如下：java 设置环境变量 path c:/jkd6/bin classpath c:/jdk6/lib/dt.jar; c:/jdk6/lib/tools.jar
接下来在dos中输入：
I've tried the command: set classpath=%classpath%;.; It works! Amazing Thanks.
