Make jackson library dependencies optional

[olaf-otto]

Initially, both AEM 6.1 and 6.2 shipped with a version of com.adobe.cq.social.cq-social-scf-api exposing only part of the jackson framework libraries residing on its internal class path. Consequently, these imports were either not usable or led to ClassNotFound Exceptions, as Spring naturally expected the jackson libraries to be fully present, not just partially:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/module/SimpleModule
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1109)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1054)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:778)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.access$1600(AbstractDelegatedExecutionApplicationContext.java:60)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:325)
    at org.eclipse.gemini.blueprint.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:290)
    at org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:137)
    at io.neba.core.blueprint.FelixTaskExecutor.execute(FelixTaskExecutor.java:37)
    at org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor.stageTwo(DependencyWaiterApplicationContextExecutor.java:311)
    at org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor.stageOne(DependencyWaiterApplicationContextExecutor.java:258)
    at org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor.refresh(DependencyWaiterApplicationContextExecutor.java:177)
    at org.eclipse.gemini.blueprint.context.support.AbstractDelegatedExecutionApplicationContext.refresh(AbstractDelegatedExecutionApplicationContext.java:157)
    at org.eclipse.gemini.blueprint.extender.internal.activator.LifecycleManager$1.run(LifecycleManager.java:207)
    at io.neba.core.blueprint.FelixTaskExecutor.execute(FelixTaskExecutor.java:37)
    at org.eclipse.gemini.blueprint.extender.internal.activator.LifecycleManager.maybeCreateApplicationContextFor(LifecycleManager.java:266)
    at org.eclipse.gemini.blueprint.extender.internal.activator.ContextLoaderListener$ContextBundleListener.handleEvent(ContextLoaderListener.java:87)
    at org.eclipse.gemini.blueprint.extender.internal.activator.listeners.BaseListener.bundleChanged(BaseListener.java:87)
    at org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:913)
    at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:834)
    at org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:516)
    at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:4531)
    at org.apache.felix.framework.Felix.startBundle(Felix.java:2169)
    at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:977)
    at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:964)
    at org.apache.sling.installer.core.impl.tasks.RestartActiveBundlesTask.execute(RestartActiveBundlesTask.java:75)
    at org.apache.sling.installer.core.impl.OsgiInstallerImpl.doExecuteTasks(OsgiInstallerImpl.java:847)
    at org.apache.sling.installer.core.impl.OsgiInstallerImpl.executeTasks(OsgiInstallerImpl.java:689)
    at org.apache.sling.installer.core.impl.OsgiInstallerImpl.run(OsgiInstallerImpl.java:265)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/module/SimpleModule
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1102)
    ... 36 common frames omitted
Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/module/SimpleModule
    at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:57)
    at org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:61)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.<init>(RequestMappingHandlerAdapter.java:187)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
    ... 38 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.databind.module.SimpleModule not found by org.apache.servicemix.bundles.spring-web [518]
    at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1557)
    at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:79)
    at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1998)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 46 common frames omitted

This issue was resolved by the AEM-6.2-Communities-Feature-Pack-1-1.10.60 and AEM-6.1-Communities-Feature-Pack-5-1.8.448, respectively. However, one cannot expect all customers to install these features packs as a prerequisite for installing NEBA. Thus, NEBA must handle these different situations:

• There are no Jackson library bundles present, but a partly export of jackson packages
• Jackson library bundles are present
• Neither Jackson library bundles nor partial package exports exist (e.g., pure Sling)

[olaf-otto]

In order to avoid forcing users to install the prerequisites (feature packs and service packs mentioned above), the Require-Bundle headers have been updated to:

• Be optional
• Include a version range corresponding to the package-level import version range specified in the original Spring bundles.