Spring Boot on Weblogic

Problem
I was excited to hear that Weblogic 12c supports Servlet 3.0. One of the features I was looking forward to was XML free projects, obviously I need a pom.xml. (Unless I switch to Gradle, but that's a story for another time!) I hadn't taken the time to ever try it, and I decided now was the time. So I started on a simple Spring Boot application. After I had some basic entities and a simple REST controller, I decided it was time to test deploying it. When attempting to deploy the application to Oracle Weblogic Server I ran into an error.

 <1466700792596> <BEA-149265> <Failure occurred in the execution of deployment request with ID "4230055130590606" for task "33". Error is: "weblogic.application.ModuleException: java.lang.NoSuchMethodError: org.springframework.beans.factory.xml.XmlReaderContext.getEnvironment()Lorg/springframework/core/env/Environment;"
weblogic.application.ModuleException: java.lang.NoSuchMethodError: org.springframework.beans.factory.xml.XmlReaderContext.getEnvironment()Lorg/springframework/core/env/Environment;
        at weblogic.application.internal.ExtensibleModuleWrapper.start(ExtensibleModuleWrapper.java:140)
        at weblogic.application.internal.flow.ModuleListenerInvoker.start(ModuleListenerInvoker.java:124)
        at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:216)
        at weblogic.application.internal.flow.ModuleStateDriver$3.next(ModuleStateDriver.java:211)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:42)
        at weblogic.application.internal.flow.ModuleStateDriver.start(ModuleStateDriver.java:73)
        at weblogic.application.internal.flow.StartModulesFlow.activate(StartModulesFlow.java:24)
        at weblogic.application.internal.BaseDeployment$2.next(BaseDeployment.java:729)
        at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:42)
        at weblogic.application.internal.BaseDeployment.activate(BaseDeployment.java:258)
        at weblogic.application.internal.SingleModuleDeployment.activate(SingleModuleDeployment.java:48)
        at weblogic.application.internal.DeploymentStateChecker.activate(DeploymentStateChecker.java:165)
        at weblogic.deploy.internal.targetserver.AppContainerInvoker.activate(AppContainerInvoker.java:80)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.activate(AbstractOperation.java:587)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.activateDeployment(ActivateOperation.java:150)
        at weblogic.deploy.internal.targetserver.operations.ActivateOperation.doCommit(ActivateOperation.java:116)
        at weblogic.deploy.internal.targetserver.operations.AbstractOperation.commit(AbstractOperation.java:339)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleDeploymentCommit(DeploymentManager.java:846)
        at weblogic.deploy.internal.targetserver.DeploymentManager.activateDeploymentList(DeploymentManager.java:1275)
        at weblogic.deploy.internal.targetserver.DeploymentManager.handleCommit(DeploymentManager.java:442)
        at weblogic.deploy.internal.targetserver.DeploymentServiceDispatcher.commit(DeploymentServiceDispatcher.java:176)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.doCommitCallback(DeploymentReceiverCallbackDeliverer.java:195)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer.access$100(DeploymentReceiverCallbackDeliverer.java:13)
        at weblogic.deploy.service.internal.targetserver.DeploymentReceiverCallbackDeliverer$2.run(DeploymentReceiverCallbackDeliverer.java:68)
        at weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl.run(SelfTuningWorkManagerImpl.java:548)
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)

I did some tooling around and did not have much success.

Solution
In addition to preferring the slf4j packages in the application, I also included the springframework packages since the class loaders were loading conflicting version of different spring packages. WebLogic 12.1.3 supports Spring 3.0.x officially. However Spring Boot uses 4.x versions of the various Spring frameworks.

<?xml version="1.0" encoding="UTF-8"?>
<wls:weblogic-web-app xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-web-app"
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                        http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd
                        http://xmlns.oracle.com/weblogic/weblogic-web-app
                        http://xmlns.oracle.com/weblogic/weblogic-web-app/1.4/weblogic-web-app.xsd">
    <wls:weblogic-version>12.1.1</wls:weblogic-version>
    <wls:context-root>application-name</wls:context-root>
    <wls:container-descriptor>
        <wls:prefer-application-packages>
            <wls:package-name>org.slf4j.*</wls:package-name>
            <wls:package-name>org.springframework.*</wls:package-name>
        </wls:prefer-application-packages>
    </wls:container-descriptor>
</wls:weblogic-web-app>


Resources
http://docs.spring.io/spring-boot/docs/current/reference/html/howto-traditional-deployment.html#howto-weblogic
http://stackoverflow.com/questions/21788134/spring-starting-throws-an-exception