ClassNotFoundException Error any ideas?

Question

I am new to Java and I get this error for my code:

C:\Users\Unknown\Desktop\AIB>java GreenhouseControls -f examples1.txt
Restarting system
java.lang.ClassNotFoundException: ThermostatNight
        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:268)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:164)
        at GreenhouseControls$Restart.action(GreenhouseControls.java:139)
        at tme3.Controller.run(Controller.java:32)
        at GreenhouseControls.main(GreenhouseControls.java:197)

I believe I have a classpath errors.

There you go guys I added more info. Gregory Thermostatnight is in same file — A Mahesania, Mar 21 '16 at 08:32
Gregory is right, I think. Maybe you have to use a fully qualified name (including package) for `ThermostatNight` when creating it. — Alex, Mar 21 '16 at 08:34
Can you execute `ThermostatNight tn = new ThermostatNight();` inside the Java file? — Tim Biegeleisen, Mar 21 '16 at 08:34
GreenhouseControls.java:127: cannot find symbol symbol : constructor ThermostatNight() location: class GreenhouseControls.ThermostatNight ThermostatNight tn = new ThermostatNight(); ^ — A Mahesania, Mar 21 '16 at 08:37

score 0 · Answer 1 · answered Mar 21 '16 at 08:35

0

Did you try to add your compiled java files (i.e., Event.class, ThermostatNight.class, ...) of Event.java, ThermostatNight.java to the classpath:

java -cp "target/*" GreenhouseControls -f examples1.txt

I assume that your compiled class files are in the target directory.

answered Mar 21 '16 at 08:35

Philipp

1,289
1
16
37

C:\Users\Ali\Desktop\TME3>java -cp "C:/Users/Ali/Desktop/TME3/tme3/Events.class" GreenhouseControls -f examples1.txt Exception in thread "main" java.lang.NoClassDefFoundError: GreenhouseControls – A Mahesania Mar 21 '16 at 08:43
You have to add all .class files to your classpath. Typically your IDE compiles your classes for you, if not you have to compile them using `javac`. You should place all your .class files into a folder and you can add all files to the classpath with the mentioned syntax (see, e.g., http://stackoverflow.com/questions/219585/setting-multiple-jars-in-java-classpath) – Philipp Mar 21 '16 at 08:48
ThermostatNight is not in different package it exists in one file. Only Events.java is in a different file – A Mahesania Mar 21 '16 at 09:01
But you only add the Event.class in your classpath... you also have to add the .class file which contains the GreenhouseControls class and the ThermostatNight class – Philipp Mar 21 '16 at 09:04
This is what i get, once I did your trick java.lang.InstantiationException: GreenhouseControls$ThermostatNight at java.lang.Class.newInstance0(Class.java:335) at java.lang.Class.newInstance(Class.java:303) at GreenhouseControls$Restart.action(GreenhouseControls.java:140) at tme3.Controller.run(Controller.java:32) at GreenhouseControls.main(GreenhouseControls.java:197) – A Mahesania Mar 21 '16 at 09:07
Ok thats a different exception can you open a new post and show the full stack trace? – Philipp Mar 21 '16 at 09:15

score 0 · Answer 2 · answered Mar 21 '16 at 08:52

0

I solved in this way.

java -classpath YourProjectWar.jar com.yourpackage.ClassWithMain -f examples1.txt

answered Mar 21 '16 at 08:52

Andrea Girardi

4,337
13
69
98

ClassNotFoundException Error any ideas?

2 Answers2