Maven dependency order issue inside spring boot project importing other project jar - spring

Question

I am new to spring world, I have 2 projects,
Notification project which uses Spring boot
Authenticate project which is a normal Spring security project
the 1st project is depending on the second one which I import using maven
my first project is just a rest endpoint where the authenticationprovider and authenticationfilter is based on the second project
my second project basically contains 2 things
1. component annotated CustomAuthenticationProvider extends AuthenticationProvider from spring security
2. customFilter extending AbstractAuthenticationProcessingFilter
in my first project I also uses springfox swagger which I import this way
*other dependency above*
<dependency>
<groupId>com.mycompany.authenticate</groupId>
<artifactId>authenticate</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.6.1</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.6.1</version>
</dependency>
and it throws an error where it says that
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'apiDescriptionReader' defined in URL [jar:file:/C:/Users/hans/.m2/repository/io/springfox/springfox-spring-web/2.6.1/springfox-spring-web-2.6.1.jar!/springfox/documentation/spring/web/scanners/ApiDescriptionReader.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cachingOperationReader' defined in URL [jar:file:/C:/Users/hans/.m2/repository/io/springfox/springfox-spring-web/2.6.1/springfox-spring-web-2.6.1.jar!/springfox/documentation/spring/web/scanners/CachingOperationReader.class]: Bean instantiation via constructor failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [springfox.documentation.spring.web.scanners.CachingOperationReader]: Constructor threw exception; nested exception is java.lang.NoSuchMethodError: com.google.common.cache.CacheBuilder.maximumSize(J)Lcom/google/common/cache/CacheBuilder;
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866) ~[spring-context-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) ~[spring-context-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
at com.styletribute.notification.NotificationApplication.main(NotificationApplication.java:12) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cachingOperationReader' defined in URL [jar:file:/C:/Users/hans/.m2/repository/io/springfox/springfox-spring-web/2.6.1/springfox-spring-web-2.6.1.jar!/springfox/documentation/spring/web/scanners/CachingOperationReader.class]: Bean instantiation via constructor failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [springfox.documentation.spring.web.scanners.CachingOperationReader]: Constructor threw exception; nested exception is java.lang.NoSuchMethodError: com.google.common.cache.CacheBuilder.maximumSize(J)Lcom/google/common/cache/CacheBuilder;
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:279) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
... 19 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [springfox.documentation.spring.web.scanners.CachingOperationReader]: Constructor threw exception; nested exception is java.lang.NoSuchMethodError: com.google.common.cache.CacheBuilder.maximumSize(J)Lcom/google/common/cache/CacheBuilder;
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:154) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:122) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:271) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
... 32 common frames omitted
Caused by: java.lang.NoSuchMethodError: com.google.common.cache.CacheBuilder.maximumSize(J)Lcom/google/common/cache/CacheBuilder;
at springfox.documentation.spring.web.scanners.CachingOperationReader.<init>(CachingOperationReader.java:45) ~[springfox-spring-web-2.6.1.jar:2.6.1]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142) ~[spring-beans-4.3.8.RELEASE.jar:4.3.8.RELEASE]
... 34 common frames omitted
lastly the way my spring security config is
#Configuration
#EnableWebSecurity
#EnableGlobalMethodSecurity(prePostEnabled = true)
#ComponentScan(basePackages = {"com.mycompany.authenticate"})
public class SecurityConfiguration extends WebSecurityConfigurerAdapter{
#Autowired
private AuthenticationManager authenticationManager;
#Autowired
private CustomAuthenticationProvider auths;
#Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.authenticationProvider(auths);
}
}
the way I configure my swagger is
#Configuration
#EnableSwagger2
public class SwaggerConfiguration {
#Bean
public Docket api() {
return new Docket(DocumentationType.SWAGGER_2)
.select()
.apis(RequestHandlerSelectors.any())
.paths(PathSelectors.any())
.build();
}
}
the pom xml inside my authenticate is
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${org.springframework-version}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j-version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.16</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.5.3</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-web</artifactId>
<version>${org.springframework.security-version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.3</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok-maven-plugin</artifactId>
<version>1.16.4.1</version>
</dependency>
<dependency>
<groupId>org.yaml</groupId>
<artifactId>snakeyaml</artifactId>
<version>1.18</version>
</dependency>
</dependencies>
but when I change the order of the maven in the first project which become
*other dependency above*
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.6.1</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.6.1</version>
</dependency>
<dependency>
<groupId>com.mycompany.authenticate</groupId>
<artifactId>authenticate</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
it doesnt show any error, may I know why is this happening ?
Your help is really appreciated

Answer 1

It looks like you have two different versions of the jar that contains com.google.common.cache.CacheBuilder on the classpath; one that is a transtive dependency of SpringFox and another that is a transitive dependency of your authenticate module. You could confirm this by running mvn dependency:tree on your notification project. When Maven encounters two different versions of the same dependency it needs to choose which one to use.
Maven resolves version conflicts using a nearest wins strategy, where nearest means the shortest route from the conflicted module to the root of the dependency graph. If two modules are the same distance from the root of the graph, then the version that is pulled in by the dependency nearest the top of the pom.xml is used. I believe that it's this latter point that explains why swapping the order of the dependencies in your pom fixes the failure that you were seeing.