Cannot invoke method toUpperCase() on null object
java.lang.NullPointerException: Cannot invoke method toUpperCase() on null object
        at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:88)
        at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:45)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
        at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:32)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
        at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:54)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
        at com.kameleoon.core.ImageCrawlingService.crawlInterestsForImages(ImageCrawlingService.groovy:45)
        at com.kameleoon.core.ImageCrawlingService$crawlInterestsForImages.call(Unknown Source)
        at com.kameleoon.UpdateMentalistDataJob$_execute_closure1.doCall(UpdateMentalistDataJob.groovy:39)
        at com.kameleoon.UpdateMentalistDataJob$_execute_closure1.doCall(UpdateMentalistDataJob.groovy)
        at sun.reflect.GeneratedMethodAccessor6291.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:207)
        at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.call(PogoMetaMethodSite.java:68)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112)
        at com.kameleoon.core.CommonService$_closure2.doCall(CommonService.groovy:63)
        at sun.reflect.GeneratedMethodAccessor2188.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1085)
        at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1110)
        at groovy.lang.MetaClassImpl.invokePropertyOrMissing(MetaClassImpl.java:1124)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1087)
        at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1110)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:909)
        at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:39)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
        at com.kameleoon.UpdateMentalistDataJob.execute(UpdateMentalistDataJob.groovy:39)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at grails.plugins.quartz.GrailsJobFactory$GrailsJob.execute(GrailsJobFactory.java:102)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)