Linux running/compiling from Command Line?

[arcelivez]

Hi,

Well when i try to run class files with java I get this:

arturas@Universe:~/NetBeansProjects/NTPApplication/build/classes/NTP2$ java NTPServer
Exception in thread "main" java.lang.NoClassDefFoundError: NTPServer (wrong name: NTP2/NTPServer)
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Could not find the main class: NTPServer. Program will exit.

When I try compiling with javac I get:

arturas@Universe:~/NetBeansProjects/NTPApplication/src/NTP2$ javac NTPServer.java 
NTPServer.java:33: cannot find symbol
symbol  : class NTPThread
location: class NTP2.NTPServer
            new NTPThread(serverSocket.accept(), instanceNr).start();
                ^
1 error

That's sad, I never succeeded runing JAVA apps from command line, I need somebody to teach me please...

[Norm]

NoClassDefFoundError: NTPServer (wrong name: NTP2/NTPServer)

The class name includes a package. Include the package name with the classname:
java NTP2.NTPServer

Be sure to have the classpath point to the folder that contains the NTP2 folder.

[eRaaaa]

even if he gets compiler errors? ....
looks for me more that the compiler can find the NTPThread class....
NTPServer.java:33: cannot find symbol
symbol : class NTPThread
location: class NTP2.NTPServer
new NTPThread(serverSocket.accept(), instanceNr).start();

[Norm]

even if he gets compiler errors? ..

The first error message says that the java command found a class file but it had the wrong classname.

I didn't address the second problem which looks like a missing class definition problem. That would probably be a classpath problem also with the packages part of it.

[kjkrum]

To add to what Norm said... you typed this:

arturas@Universe:~/NetBeansProjects/NTPApplication/build/classes/NTP2$ java NTPServer

The default classpath (in the $CLASSPATH environment variable) includes the current directory. The error message you got means that java found the file NTPServer.class in the current directory, and so expected the class in that file to be called NTPServer. But it was called NTP2.NTPServer.

From that same prompt, you could have typed this:

cd ..
java NTP2.NTPServer

That would have given you the result you expected. Or you could have typed this:

java -cp .. NTP2.NTPServer

It's been forever since I compiled on the command line. I think javac has the same -cp switch.