Develop Reference

Spring Boot 2 Upgrade not able to resolve class name as property

We have an application where one of our internal libraries has defined a bean like this
<bean id="myBean" class="${myBean.type}"/>
We have a Spring Cloud Config Server which feeds properties to this application on startup, which also contains the property myBean.type. This setup is currently working fine with no issues. I then made the following change to my pom
Earlier
<spring.boot.version>1.5.16.RELEASE</spring.boot.version>
<spring.cloud.version>Edgware.RELEASE</spring.cloud.version>
<spring.version>4.3.19.RELEASE</spring.version>
Now
<spring.boot.version>2.0.9.RELEASE</spring.boot.version>
<spring.version>5.0.13.RELEASE</spring.version>
<spring.cloud.version>Finchley.SR2</spring.cloud.version>
Then I started getting this error on startup
An attempt was made to call the method org.springframework.beans.factory.support.BeanDefinitionBuilder.addConstructorArg(Ljava/lang/Object;)Lorg/springframework/beans/factory/support/BeanDefinitionBuilder; but it does not exist. Its class, org.springframework.beans.factory.support.BeanDefinitionBuilder, is available from the following locations:
jar:file:/I:/Library/MavenRepository/org/springframework/spring-beans/5.0.13.RELEASE/spring-beans-5.0.13.RELEASE.jar!/org/springframework/beans/factory/support/BeanDefinitionBuilder.class
It was loaded from the following location:
file:/I:/Library/MavenRepository/org/springframework/spring-beans/5.0.13.RELEASE/spring-beans-5.0.13.RELEASE.jar
Action:
Correct the classpath of your application so that it contains a single, compatible version of org.springframework.beans.factory.support.BeanDefinitionBuilder
Looking at this, I excluded the artifact org.apache.cxf:cxf-api:jar:2.7.18:compile from all the jars that depended on it & upgraded cxf jars versions to 3.2.5. Now the startup is going ahead but it is giving me the following error:
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [${myBean.type}] for bean with name 'myBean' defined in class path resource [xyz.xml]; nested exception is java.lang.ClassNotFoundException: ${myBean.type}
I am not sure if removal of cxf-api is causing this issue, or upgrade of Spring Boot 2, or is it something else that is going wrong here!

ConflictingBeanDefinitionException even after deleting a class

I am developing a simple maven + spring application and i am getting the following error. It says two of my classes have a conflict. so i deleted the second class but i am still getting the same error. I tried restarting the server but it still says my class exists. Can somebody help?
Exception while loading the app : java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [com.nibm.config.RootConfig]; nested exception is org.springframework.context.annotation.ConflictingBeanDefinitionException: Annotation-specified bean name 'employeeController' for bean class [com.nibm.hibernate.controller.EmployeeController] conflicts with existing, non-compatible bean definition of same name and class [com.nibm.controller.EmployeeController]

I was able to solve a similar problem by using IntelliJ's function "Rebuild".
The reason was an orphan .class file after the corresponding .java file had already been deleted.

You get the exception because you have two spring beans of the same class.
This exception is thrown by
org.springframework.context.annotation.ClassPathBeanDefinitionScanner#isCompatible
And looking at that implementation it looks as if you create a bean of type EmployeeController in your RootConfig and additionally by ComponentScan.
To fix the problem remove the bean from the RootConfig or change your ComponentScan, so this bean is not found by it.
You can set a breakpoint in the constructor of EmployeeController. From the stack you can get more information about how and why the bean is created.

I faced the same problem and it was because class with same name exist at two locations as mentioned in the Exception itself which are conflicting and after removing one issue got fixed.

I was getting this same ConflictingBeanDefinitionException..."conflicts with existing, non-compatible bean definition of same name and class" when running JUnit tests with #RunWith(SpringRunner.class)/ #SpringBootTest from inside Intellij.
Execution via gradle:build of the same tests were running fine.
This began to happen after I had refactored the packaging of several #Components which lead me to believe something was holding a reference to the class under it's previous package name.
No amount of gradle build/clean would seem to clear it.
Doing a Build -> Rebuild Project in IntelliJ was what cleared this issue for me.

Referencing an external class from a Jersey REST web app

I am trying a simple example of creating a RESTful API. I used the Maven jersey-quickstart-webapp archtype to create a Jersey web app. In a separate project I created a simple class: SimpleClass, which only has one method that returns "hello". I am trying to create an instance of that class in my method in the web app (I am using the default MyResource class) and call its method to get "Hello". I exported the project with the SimpleClass to a JAR file, and added that file to the build path for my Jersey project, and imported the relevant package.
When I run the web app on a local server, and call the MyResource method, I get an error with the root cause (just the top few rows):
java.lang.NoClassDefFoundError: Lorg/test/simple/SimpleClass;
java.lang.Class.getDeclaredFields0(Native Method)
java.lang.Class.privateGetDeclaredFields(Class.java:2583)
java.lang.Class.getDeclaredFields(Class.java:1916)
So, it can't find the SimpleClass class.
What am I doing wrong here? I'd really appreciate any help!
Thanks,
Yariv.
New info: I tried to create a RESTful web service without Maven. I successfully created the project with a simple "Hello World" example, and then I tried to add my own class from another project: I imported the .jar, added it to the build path, and created a class in the web service that creates an instance of my class when a GET is made to the server. My class happens to include (as members) instances of other classes, one of which connects to a MongoDB database, and when I run the service, I again get a HTTP 500 error as follows:
A MultiException has 2 exceptions. They are:
1. java.lang.NoClassDefFoundError: com/mongodb/DBObject
2. java.lang.IllegalStateException: Unable to perform operation: create on org.notes.server.NotesServer
Adding the MongoDB jar to the web project did not help. I must be missing something big here. What should I do to call code I created in another project (with a set of dependencies there) in my web service?
I'll appreciate any help I can get, I am getting nowhere with this...

I was able to resolve all these issues by adding all the relevant JARs to the deployment assembly (right-click on the project, click Properties, then select Deployment Assembly and add all the JARs that my class depends on, as well as its own JAR).
Thanks for your help, radai!

ambiguous mapping while deploying

I'm using Jenkins 1.6.20 (Git Client Plugin 1.18.0, Git Plugin 2.4.0) to get the Java application code from bitbucket.org and deploy it to Apache Tomcat 8.0.23.
The error appears while deploying and looks like:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/spr$
public java.util.List by.ipps.accounting.ws.PositionWS.getEmployeePost(java.lang.Long)
to {[/positionListJson/{id}],methods=[GET],params=[],headers=[],consumes=[],produces=[application/json],custom=[]}: There is already 'resourceWS' bean method
public by.ipps.accounting.model.Employee.EmployeePost by.ipps.accounting.ws.ResourceWS.getEmployeePost(java.lang.Long) mapped.
bla-bla-bla ... so many errors ...
Caused by: java.lang.IllegalStateException: Ambiguous mapping found. Cannot map 'positionWS' bean method
public java.util.List by.ipps.accounting.ws.PositionWS.getEmployeePost(java.lang.Long)
to {[/positionListJson/{id}],methods=[GET],params=[],headers=[],consumes=[],produces=[application/json],custom=[]}: There is already 'resourceWS' bean method
public by.ipps.accounting.model.Employee.EmployeePost by.ipps.accounting.ws.ResourceWS.getEmployeePost(java.lang.Long) mapped.
The problem is that the class (with annotation #Controller) PositionWS with method getEmployeePost was renamed to ResourceWS a week ago, so exists no more, so I should not get this error.
To fix this I have to create a blank PositionWS controller (with no methods in it), commit & push that to bitbucket (and delete (cus i really don't need it) later and commit & push).
It seems to be like a bug in any of the applications I use. I can't find out in which app there is a bug to report it. Tell me please, if anyone faced such problems.

The heart of the issue was in incorrect configuration of Jenkins, it was my fault.
When I was configuring Jenkins I set maven goal as "install", but it must be "clean install". According to this Jenkins never deleted old files and kept them, so got a lot of issues of different kinds and with different log messages.
Due to Jenkins working specialty it downloads project files and try to assemble it on path /var/lib/jenkins/jobs/<projectName>/workspace/target/.
So I've drop the data in this folder and afterwards set maven goal to "clean install" and that fixed the issue.

Annotation-specified bean name conflicts with existing, non-compatible bean definition

I'm using Spring 2.5.4 and am creating a Java application that I'm deploying onto Weblogic.
I have a class in an external library (which included in the WEB-INF/classes directory of the resulting WAR file of my application) that I want to use in my code. I've created an instance variable for an object of the class in my code and added the #Autowired annotation and a getter and setter. In my application context file I have declared a bean of the library class' type and added the following:
<context:annotation-config />
<context:component-scan base-package="com.mycompany" />
... in order to register an AutowiredAnnotationBeanPostProcessor that will scan the classes and process the annotation.
When I try and deploy the application, I get the following error:
java.lang.IllegalStateException: Annotation-specified bean name 'myBean' for bean
class [com.mycompany.package.ClassName] conflicts with existing, non-compatible
bean definition of same name and class [com.mycompany.otherPackage.ClassName]
I think this is because there's a class in the library which has the same name as one in my application code (both class' package names start with "com.mycompany"). Nb. this is NOT the class that I have added, but a different one. Is there any way I can circumvent this problem without changing the name of the class in my application?
Thanks for any assistance.

Old question but throwing my 2c of bad experience with similar problem.
If you have 2 classes with same name, but in different packages was there a time when you had your other class referenced by the failing Spring context? If so, I'd recommend to clean the AS cached files (typically the place where the WAR is extracted), clean/rebuild your WAR and deploy again. Restarting the app server is also recommended.
I found that application servers and web containers alike (Weblogic, WAS, Jboss, Tomcat) tend to leave behind the old classes and when application is deployed those stale .class files are loaded in JVM via some old references, which most of the time messes up the Spring context loader.
Typical scenario is when you have renamed/moved a class from one package to another, or even kept the package name the same but moved it to another module (jar). In such cases cached (left over) files in the AS work directory can cause big headaches. Wiping out the work directory in your AS should resolve the issue outright.

You should use #qualifier to avoid this kind of conflict please refer section 3.9.3.

I fixed the problem by removing the autowiring completely and accessing the bean by explicitly creating a reference to it through the application context and the getBean() method.

This would better fit as a comment to #Pavel Lechev's answer, but I don't have enough rep to comment yet.
For other's finding this, here's what I did to solve this problem. I am using Wildfly 9.0.2.Final and, IntelliJ IDEA 2016.1.3 Build #IU-145.1617. These steps should presumably work with JBoss as well.
Stop Wildfly server.
Navigate to $WILDFLY_HOME/standalone/. Delete the three following folders: lib/, log/ and temp/.
In IntelliJ, Build > Build Artifacts > All Artifacts > Clean (or just the artifacts you are deploying).
In IntelliJ, Build > Rebuild Project
Restart Wildfly and redeploy your artifact(s).
These steps remedied my issue of duplicate bean names detected in the Spring context after refactoring a package name upstream from a couple of Controllers.