Reporting | NullPointerException: Cannot invoke method sort() on null object

[jmiranda]

2013-12-16 01:22:30,274 ERROR  GrailsExceptionResolver - Exception occurred when processing request: [GET] /openboxes/inventory/listOutOfStock
Stacktrace follows:
java.lang.NullPointerException: Cannot invoke method sort() on null object
    at org.pih.warehouse.inventory.InventoryService.getQuantityByProductAndInventoryItemMap(InventoryService.groovy:1087)
    at org.pih.warehouse.inventory.InventoryService$getQuantityByProductAndInventoryItemMap.callCurrent(Unknown Source)
    at org.pih.warehouse.inventory.InventoryService$getQuantityByProductAndInventoryItemMap.callCurrent(Unknown Source)
    at org.pih.warehouse.inventory.InventoryService.getQuantityByProductMap(InventoryService.groovy:1161)
    at org.pih.warehouse.inventory.InventoryService$$FastClassByCGLIB$$a7f866ff.invoke(<generated>)
    at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
    at org.pih.warehouse.inventory.InventoryService$$EnhancerByCGLIB$$b44803aa.getQuantityByProductMap(<generated>)
    at org.pih.warehouse.inventory.InventoryService$getQuantityByProductMap.call(Unknown Source)
    at org.pih.warehouse.inventory.InventoryController$_closure22.doCall(InventoryController.groovy:454)
    at org.pih.warehouse.inventory.InventoryController$_closure22.doCall(InventoryController.groovy)
    at grails.plugin.springcache.web.GrailsFragmentCachingFilter.doFilter(GrailsFragmentCachingFilter.groovy:66)
    at net.sf.ehcache.constructs.web.filter.Filter.doFilter(Filter.java:86)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
2013-12-16 01:22:30,274 [http-apr-8080-exec-1] ERROR errors.GrailsExceptionResolver  - Exception occurred when processing request: [GET] /openboxes/inventory/listOutOfStock