ClassNotFoundException & NoClassDefFoundError (Why??)

Question

I want to make Cytoscape Simple App(It is like a Plug in Program).

So I should make a .jar file, and install it in Cytoscape Program.

My problem is the following:

I'll show you 2 cases.

There are 6 classes(A,B,C,D,E,F), and 2 .jar file(that represent other API)

A (CytoscapeLeapMotionApp) is the main class(actually it doesn't include main method, but it is the first class run when App is installed).

C,E are classes that I made.

B,D are in 1.jar.

F(Listener) is in 2.jar(leap).

Case 1

A extends B

C instance is created at A

C extends D

E instance is created at C

E extends F

Result:

Caused by: java.lang.NoClassDefFoundError: com/leapmotion/leap/Listener     at
CytoscapeLeapMotionApp.<init>(CytoscapeLeapMotionApp.java:9)    ... 21
more

Caused by: java.lang.ClassNotFoundException:
com.leapmotion.leap.Listener    at
java.net.URLClassLoader$1.run(URLClassLoader.java:202)  at
java.security.AccessController.doPrivileged(Native Method)  at
java.net.URLClassLoader.findClass(URLClassLoader.java:190)  at
java.lang.ClassLoader.loadClass(ClassLoader.java:306)   at
java.lang.ClassLoader.loadClass(ClassLoader.java:247)   ... 22 more

Case 2

A extends B

C instance is created at A

C extends D

F instance is created at C

Result:

Good, no errors!

Following is E extends F

public final class SampleListener extends Listener {
    //nothing
}

How are you running the application? Within an IDE or via the command line? — JamesB, Jul 21 '14 at 08:39
@ray I'm Sorry, cause I'm a beginner, I don't know what namespace means. :( — DAESEONG KIM, Jul 21 '14 at 08:47
@JamesB I make a .jar file that include above all classes. And Start main Program(Cytoscape), install .jar file. — DAESEONG KIM, Jul 21 '14 at 08:47
@JamesB I copy my .jar file in Cytoscape's App directory. Then it is intalled! — DAESEONG KIM, Jul 21 '14 at 08:53
@DaeSungKim What is the structure of the jar file that you created? — JamesB, Jul 21 '14 at 09:45
lib META-INF A.class C.class E.class In lib folder, there are 2.jar and some .dll file. In META-INF, there is MANIFEST.MF file. — DAESEONG KIM, Jul 22 '14 at 00:09

score 0 · Answer 1 · answered Jul 21 '14 at 08:34

0

This error

Caused by: java.lang.NoClassDefFoundError: com/leapmotion/leap/Listener at CytoscapeLeapMotionApp.(CytoscapeLeapMotionApp.java:9) ... 21 more

suggests that when CytoscapeLeapMotionApp is run, the type com.leapmotion.leap.Listener is not on the classpath.

You have indicated that this type is within a jar file named 2.jar so this needs to be added to the classpath before you retry.

answered Jul 21 '14 at 08:34

JamesB

7,774
2
22
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But when I try case 2, It also use class F(that is in 2.jar). But there are no errors. I don't know why this happen. – DAESEONG KIM Jul 21 '14 at 08:43
@DaeSungKim How are you running both cases? – JamesB Jul 21 '14 at 08:46

ClassNotFoundException & NoClassDefFoundError (Why??)

1 Answers1