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Flapping compilation error gradle java build

I've never seen anything like this before and have asked everyone at work and they are not sure either. I am getting a compilation error on a ./gradlew assemble build but it does not occur consistently. The error is shown below. What is particularly confusing about this is both AbstractDateRangeConfig and DynamicRequestComponent are used throughout the code base in other classes and these compile fine consistently. DynamicRequestComponent is a spring annotation the other class is an internal class. There is another class with an almost identical setup, the only difference I can see is that there is also an inner class with a #Configuration annotation in the class which fails compilation. Does anyone have any suggestion on what might cause a flapping compilation error like this?
:frontend:compileJava/mnt/jenkins/workspace/frontend/src/main/java/com/frontend/app/controller/group/forecast/NewGroupForecastReport.java:358: error: cannot find symbol
public static class NewGroupForecastReportConfig extends AbstractDateRangedConfig {
^
symbol: class AbstractDateRangedConfig
location: class NewGroupForecastReport
/mnt/jenkins/workspace/duetto_app_basic2/frontend/src/main/java/com/frontend/app/controller/group/forecast/NewGroupForecastReport.java:357: error: cannot find symbol
#DynamicRequestComponent
^
symbol: class DynamicRequestComponent
location: class NewGroupForecastReport
2 errors
FAILED
Edit: It is not the #Configuration annotation causing it. I removed that part of the code and still see the error

Appears to be resolved by pulling out the inner class into a separate class file. Believe the error had something to do with the way Spring scans for annotations

Kotlin/KAPT Generated Kotlin class is not recognized as class member, but it does inside of methods

I have written an annotation processor that generates a builder class for my classes annotated with #DataBuilder
#Target(AnnotationTarget.CLASS)
#Retention(AnnotationRetention.SOURCE)
annotation class DataBuilder
My classes annotated with this annotation are located in the com.my.package.model package and the generated builder class is also located in the same package com.my.package.model but in the generated directory of course build/generated/source/kapt/debug/com/my/package/model/MyModelBuilder.kt, I can use these generated classes fine inside of my model classes(written in Kotlin)
BUT I can NOT use the generated MyModelBuilder Kotlin class inside of a java class as a class member
package com.my.package.home;
import com.my.package.model.MyModelBuilder;
public class Home {
MyModelBuilder builder; // <=== AS recognizes the class, but I'm having an compilation issue
}
Android Studio recognizes the class, but I’m having this compilation issue
com/my/package/home/Home.java:4: error: cannot find symbol
MyModelBuilder builder;
^
symbol: class MyModelBuilder
location: class Home
it’s weird because I can use this generated builder class only inside of methods, this code compiles fine:
package com.my.package.home;
import com.my.package.model.MyModelBuilder;
public class Home {
public void hello() {
MyModelBuilder builder;
}
}
could somebody here help me to understand this behavior and how to fix this? In advance, thanks!
UPDATE
I just created this repo with the necessary code to replicate the issue
https://github.com/epool/HelloKapt
The project works fine after cloning and running, to replicate the issue please un-comment this line https://github.com/epool/HelloKapt/blob/master/app/src/main/java/com/nearsoft/hellokapt/app/MainActivity.java#L13
Note: If I convert my MainActivity.java class to Kotlin(MainActivity.kt) the issues is NOT reproducible and works fine, but I don’t want to do so due to some project limitations so far
Kotlin Issue: https://youtrack.jetbrains.net/issue/KT-24591

Looking at your Github project, I notice that you don't declare a dependency on kotlin-stdlib-jdk7 in the app module. When I build the module, compiler emits the following warnings:
warning: unknown enum constant AnnotationTarget.CLASS
reason: class file for kotlin.annotation.AnnotationTarget not found
warning: unknown enum constant AnnotationRetention.SOURCE
reason: class file for kotlin.annotation.AnnotationRetention not found
warning: unknown enum constant AnnotationTarget.CLASS
reason: class file for kotlin.annotation.AnnotationTarget not found
Since kotlin-stdlib-jdk7 is declared as implementation in the annotations module, the app module doesn't see it as a transitive dependency, that might be the reason why compilation fails. To fix it, you should probably declare the correct dependency in the app module, or at least use apiElements scope for kotlin-stdlib-jdk7 in annotations.
The fact that the IDE doesn't notify you that compilation failed might be a tools bug, but there's definitely no underlying Kotlin compiler issue.

Magnolia - Instantiate fail with a module class

When I need starting a command with scheduler I have the next error in console:
I'm going to line 66 that log said me and i can see this:
This class WsProuser has a Null pointer Exception when i try get the instance. This class is a default class of module where i saved some configurations. This is a part of META-INF xml where i reference this class:
And this is the implementation of this class:
For finish, this is the config where i save the values that i need in the command:
¿Why i have this NullPointer Exception when magnolia should instanciate automating this class?

I don't have any information about your package structure, but I think the <class /> element from module descriptor should be:
<class>es.vass.magnolia.module.wsprouser.WsProuser</class>
It looks like you are repeating the class name.
Update: After reading the log, I saw that the NPE is thrown when the module ui-admincentral is started. At that time, your custom module ws-prouser-prosegur-intra-module is not started yet, so the static instance is still null. In order to work this way you should add a dependency to your module in ui-admincentral, but given that this is a magnolia module, you can't do that. What I would recommend is to inject a Provider<WsProuser> in your CommandGenerator and use that instead of WsProuser.getInstance(). Then use this provider where you actually need it, not in constructor.

java.lang.NoClassDefFoundError only in particular conditions

My problem is that when class B tries to use A.check() my execution stops due to a java.lang.NoClassDefFoundError.
So here is my class configuration. NB: the classes are in the same packages and I have already checked that the A.class file is placed where it should be.
public class A{
// vars
// declare some public method
public synchronized static boolean check(){
//do stuff, log some info and return boolean
}
}
public class B implements Runnable{
public void run() {
A.check();
}
}
And here is my stacktrace:
java.lang.NoClassDefFoundError:
org/mypackage/A
at org/mypackage.B.run()
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException:
org/mypackage.B
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
The project is really big and class A is used lots of times before this call without any problem, so i don't think that is something relative to the classpath. Note that this is part of the last call of the software that should close up everything.
Moreover, I have two maven goals: the first one execute the questioned code without any problem, instead the second rise this error every time.

So I have solved my problem and I post here the solution so maybe can be useful for someone else.
First of all the error: java.lang.NoClassDefFoundError
This error is really different from ClassNotFoundException and this is where I'have lost a lot of time.
NoClassDefFoundError in Java is raised when JVM is not able to locate a particular class at runtime which was available at compile time. For example, if we have a method call from a class accessing any member of a Class and that class is not available during runtime then JVM will throw NoClassDefFoundError. It’s important to understand that this is different than ClassNotFoundException which comes while trying to load a class at run-time only and the name was provided during runtime, not on compile time. Many Java developer mingles this two Error and gets confused. Here I quote a really useful blog that I uesd.
So in a shorter way NoClassDefFoundError comes if a class was present during compile time but not available in java classpath during runtime.
But even with those information the problem was still there until I found the mystery: one of the reason that can place the class in a state that can be compiled but not located at runtime is that if you have static initialization that fail (e.g. in my class I had as field a static variable instantiated badly).
So remember to check for you initialization phase if you have static variables in your class this could be the reason of your java.lang.NoClassDefFoundError.
By the way I don't get why this kind of error is not raising some more meaninful errors for example java.lang.ExceptionInInitializerError or something like that.

Try to debug maven execution by running: mvn -X <your_goals>
It would be useful to see your POM file.

If you are working with spring mvc and if you made bean entry in dispatche-servlet.xml for Controller class.
Example :
<bean id="MyClass" class="com.aaps.myfolder.MyClass">
<property name="methodNameResolver">
<ref bean="methodNameResolver" />
</property>
</bean>
And if MyClass.java is not compiled & if no class file is generated in classes folder of your project folder then it wil show java.lang.NoClassDefFoundError.
So check whether the MyClass.class is created or not in classes folder if you are working with spring mvc.

Does Class A have anything that is done in a static block. You can get this exception even if a class is being loaded and static blocks fails for any reason reason. try to put in logging to see if something like this is happening.

NoClassDefFoundError exception in my thread

I get this error:
Exception in thread "http-server" java.lang.NoClassDefFoundError: org/w3c/jigmonitor/ReplyServer
but I don't undestand why. Could someone explain why does this happen?
This is the class that causes the problem:
public class ReplyServer implements Serializable
{
public ReplyServer()
{
super();
}
}

It looks like the class you're defining isn't being found by something that's trying to load it. In my experience this is caused by one of three problems:
Your package declaration for the class is not correct. In this case something on the http-sever thread is expecting your class to be declared in the package org.w3c.jigmonitor.
Your source file is not located in the correct directory. In this case, your source file should be located in a directory structure like "org/w3c/jigmonitor/", providing that's the package you actually want.
The path of the compiled class for ReplyServer is not in the classpath of your JVM. You can check this by looking at the classpath used to start your JVM and seeing if the class is actually there or not. In most generic setups servlet setups there will be a "WEB-INF/classes" folder for you to go poke around in.
Good luck!
(The link David posted gives a ton of information on this type of issue and the possible causes. I would recommend tucking that away for later)