Conflict problem building the Spring boot application - spring

Question

I have a problem building the spring boot application. We need to build the project with the 'lib/bin/conf' structure using the maven. I did it with another project and there is no problem. But now, a conflict occurred and an action is recommended.
Description:
An attempt was made to call a method that does not exist. The attempt was made from the following location:
org.springframework.context.support.GenericApplicationContext.setApplicationStartup(GenericApplicationContext.java:165)
The following method did not exist:
'void org.springframework.beans.factory.support.DefaultListableBeanFactory.setApplicationStartup(org.springframework.core.metrics.ApplicationStartup)'
The method's class, org.springframework.beans.factory.support.DefaultListableBeanFactory, is available from the following locations:
jar:file:/target/OrderManager/libs/communication-latest.jar!/org/springframework/beans/factory/support/DefaultListableBeanFactory.class
jar:file:target/OrderManager/libs/spring-beans-5.3.8.jar!/org/springframework/beans/factory/support/DefaultListableBeanFactory.class
The class hierarchy was loaded from the following locations:
org.springframework.beans.factory.support.DefaultListableBeanFactory: file:target/OrderManager/libs/communication-latest.jar
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory: file:target/OrderManager/libs/communication-latest.jar
org.springframework.beans.factory.support.AbstractBeanFactory: file:target/OrderManager/libs/communication-latest.jar
org.springframework.beans.factory.support.FactoryBeanRegistrySupport: file:target/OrderManager/libs/communication-latest.jar
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry: file:target/OrderManager/libs/communication-latest.jar
org.springframework.core.SimpleAliasRegistry: file:target/OrderManager/libs/communication-latest.jar
Action:
Correct the classpath of your application so that it contains a single, compatible version of org.springframework.beans.factory.support.DefaultListableBeanFactory
How can I solve this problem? I'm using a lib named communication that is provided by our company.
This is my pom file.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example.artifact</groupId>
<artifactId>ordermanager</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Order Manager Component</name>
<properties>
<java.version>11</java.version>
<spring-cloud.version>Hoxton.SR7</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
<version>2.4.2</version>
</dependency>
<dependency>
<groupId>com.excample.myArtifact</groupId>
<artifactId>communication</artifactId>
<version>latest</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>appassembler-maven-plugin</artifactId>
<version>2.1.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>assemble</goal>
</goals>
</execution>
</executions>
<configuration>
<assembleDirectory>target/OrderManager</assembleDirectory>
<repositoryName>libs</repositoryName>
<configurationDirectory>conf</configurationDirectory>
<configurationSourceDirectory>src/main/resources</configurationSourceDirectory>
<copyConfigurationDirectory>true</copyConfigurationDirectory>
<repositoryLayout>flat</repositoryLayout>
<useWildcardClassPath>true</useWildcardClassPath>
<programs>
<program>
<mainClass>com.example.artifact.ordermanager.OrderManagerComponentApplication</mainClass>
<id>OrderManager</id>
</program>
</programs>
</configuration>
</plugin>
</plugins>
</build>
</project>

Answer 1

the answer is already there:
Correct the classpath of your application so that it contains a single, compatible version of org.springframework.beans.factory.support.DefaultListableBeanFactory
Your problem is, that you've got 2 JAR files containing the same class org.springframework.beans.factory.support.DefaultListableBeanFactory. These are:
/target/OrderManager/libs/communication-latest.jar
target/OrderManager/libs/spring-beans-5.3.8.jar
You have to remove one of them. Now I don't know your project and architecture, but if you're using a company customized spring library, then you should remove the standard spring jar. Use maven's exclude mechanism for that, it is a so called transient dependency, so you didn't define it explicitly, but one of the dependencies you defined is dependending on that.
First you have to find out which dependency brings that spring-beans dependency in. Use maven's dependency tree to do that:
mvn dependency:tree
You can also use dependency analysis or read about the whole dependency management.
If you want to kick out the communication-latest.jar you should just remove the following in your pom.xml:
<dependency>
<groupId>com.excample.myArtifact</groupId>
<artifactId>communication</artifactId>
<version>latest</version>
</dependency>

Answer 2

For resolving this conflict you can use excludes-dependencies https://maven.apache.org/guides/introduction/introduction-to-optional-and-excludes-dependencies.html
In this case, it should be
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
from
<groupId>com.excample.myArtifact</groupId>
<artifactId>communication</artifactId>

Answer 3

The problem was with version mismatching with the spring boot that is used in the communication library rather than the spring boot of the main project. So, I changed the spring boot version to 2.3.3.RELEASE and the problem are solved.
Some friends told me to exclude the spring-beans artifact. I did not do that and version changing was enough, But testing the approaches that are told on this topic, can be useful.