Develop Reference

Spring boot autoconfigure application start fails

I've built my own starter and the autoconfigure step fails with dependency conflict.
These are the spring boot versions both my starter and upstream project are using
'spring-boot-gradle-plugin', version2.1.8.RELEASE
'spring-boot-autoconfigure', version: '2.4.1'
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APPLICATION FAILED TO START
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Description:
An attempt was made to call a method that does not exist. The attempt was made from the following location:
org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration.lambda$addResourceHandlers$0(W
ebMvcAutoConfiguration.java:411)
The following method did not exist:
'org.springframework.web.servlet.config.annotation.ResourceHandlerRegistration org.springframework.web.servlet.config.annotation.Re
sourceHandlerRegistration.addResourceLocations(org.springframework.core.io.Resource[])'
The method's class, org.springframework.web.servlet.config.annotation.ResourceHandlerRegistration, is available from the following loca
tions:
jar:file:/opt/eureka/app.jar!/BOOT-INF/lib/spring-webmvc-5.3.2.jar!/org/springframework/web/servlet/config/annotation/ResourceHandl
erRegistration.class
The class hierarchy was loaded from the following locations:
org.springframework.web.servlet.config.annotation.ResourceHandlerRegistration: jar:file:/opt/eureka/app.jar!/BOOT-INF/lib/spring-we
bmvc-5.3.2.jar!/
Action:
Correct the classpath of your application so that it contains a single, compatible version of org.springframework.web.servlet.config.an
notation.ResourceHandlerRegistration

From your log I see one of two possible problems:
Somewhere you override spring-webmvc-5.3.2 to a higher or lower version
Problem in your starter code (if it configure your WebMvc)
Try mvn dependency:tree or gradle dependencies to explore dependencies.
Attached your starter code.

I had to use spring boot 2.4.1 to avoid the conflict.

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!

Java jetty servlet container fails to resolve class dependencies

15:28:38.716 [qtp1588771273-32] WARN o.e.jetty.servlet.ServletHandler - /tp/gremlin/execute
java.lang.IllegalArgumentException: Could not resolve dependency of type:javax.transaction.TransactionManager
at org.neo4j.graphdb.DependencyResolver$Adapter$1.select(DependencyResolver.java:87) ~[neo4j-kernel-2.2.9.jar:2.2.9]
at org.neo4j.kernel.extension.KernelExtensions.resolveDependency(KernelExtensions.java:112) ~[neo4j-kernel-2.2.9.jar:2.2.9]
This is from Neo4j 2.x (the Gremlin plug-in). The package, when built and deployed as instructed at https://github.com/thinkaurelius/neo4j-gremlin-plugin, does contain the jar-file which describes this class, and Maven did download it and did install it there. But, when the server attempts to load and execute the extension, nothing is resolved.
Why?

How to fix exception: Failed to instantiate SLF4J LoggerFactory?

I am trying to write a java web crawler for semantic web using jena library. I have build project using Netbeans. I am receiving two errors:
Failed to instantiate SLF4J LoggerFactory
Reported exception:
java.lang.NoClassDefFoundError: org/apache/log4j/Level
Could not initialize class com.hp.hpl.jena.rdf.model.impl.ModelCom
at org.slf4j.LoggerFactory.bind(LoggerFactory.java:128)
I have included slf4j-api and slf4j-log both libraries.

You should also include log4j library as slf4j-log4j is just a static binder.

You should include slf4j-api-x.x.x.jar and slf4j-simple-x.x.x.jar in your classpath.

As error suggested:
Failed to instantiate SLF4J LoggerFactory
you need to place your corresponding slf4j-*-*.jar binding files into your classpath folder.
You can locate them by locate slf4j if present.
As of SLF4J version 1.6.0, if no binding is found on the class path, then slf4j-api will default to a no-operation implementation discarding all log requests.
Tomcat
If using Tomcat, these files you can copy either into /usr/share/tomcat7/lib or your webapp folder /var/lib/tomcat7/webapps/*/WEB-INF/lib.
Solr
If you're using Solr or you want use the files from there (which are included by default), you can find them in dist/solrj-lib and example/lib/ext.
See: The Simple Logging Facade for Java (SLF4J) user manual

I tried all permutation and combination but finally slf4j-api- and slf4j-simple- worked well.

Using Coda Hale Yammer Metrics library in Websphere Application Server 7

I am trying to add metrics library to existing webservice on WAS 7. I am getting below error
Error 404: javax.servlet.UnavailableException: SRVE0203E: Servlet [AdminServlet]: com.yammer.metrics.reporting.AdminServlet was found, but is missing another required class. SRVE0206E: This error typically implies that the servlet was originally compiled with classes which cannot be located by the server. SRVE0187E: Check your class path to ensure that all classes required by the servlet are present.SRVE0210I: This problem can be debugged by recompiling the servlet using only the classes in the application's runtime class path SRVE0234I
What are the other run-time dependencies required for metrics-servlet-2.2.0?
I have metrics-core-2.2.0.jar and metrics-servlet-2.2.0.jar in my WEB-INF\lib folder.
Threads, ping and healthcheck servlets work fine.

I think your missing some more required jars, are you not using maven or gradle for dependency management
Please refer here to know all required jars that metrics-servlet-2.2.0.jar depends on. http://mvnrepository.com/artifact/com.yammer.metrics/metrics-servlets/3.0.0-BETA1
My suggestion is, it is always difficult to maintain dependencies without Maven/Gradle or any other build tools :).