System.NullPointerException: Attempt to de-reference a null object line in line 30

Question

trigger UpdateApplicationStatusToEnrolled on vlocity_ins__Application__c (before update ) {
    Map <string,List<vlocity_ins__Application__c>> strMap = new Map <string,List<vlocity_ins__Application__c>>();
    set<id> appaccid = new set<id>();
    ID RT = [Select Id From RecordType Where DeveloperName = 'Medicare_Advantage'].Id;

    for(vlocity_ins__Application__c app :trigger.new)

    {

        if(app.vlocity_ins__Status__c=='Approved by CMS' & app.RecordTypeId == RT)
        {


            List<vlocity_ins__Application__c> appList = strMap.containsKey(app.Account_Id__c) ? strMap.get(app.Account_Id__c) : new List<vlocity_ins__Application__c>();
            appList.add(app);
            strMap.put(app.Account_Id__c, appList);
            system.debug('total record in map'+applist);

        }
    }
    if (strMap != null){
        List<account> accDetails=[select id,(select  id,Policy_Status__c,vlocity_ins__PolicyType__c from vlocity_ins__Policy1__r where 
                                             vlocity_ins__PolicyType__c='MEDADV' and (Policy_Status__c='Active' OR Policy_Status__c='Future' ))from account where id IN: strMap.keySet()  limit 100 ];

        system.debug('total record account'+accDetails);

        for(account  acc : accDetails){


            List<vlocity_ins__Application__c> applicatioList =  strMap.get(acc.id);

            for(vlocity_ins__Application__c application : applicatioList )
            {

                application.vlocity_ins__Status__c = 'Enrolled' ;                
            }
        }

    }  






}

Debug Logs :

07:07:45.36 (143579517)|SYSTEM_METHOD_ENTRY|[31]|System.debug(ANY) 07:07:45.36 (143586250)|USER_DEBUG|[31]|DEBUG|total recordnull 07:07:45.36 (143593327)|SYSTEM_METHOD_EXIT|[31]|System.debug(ANY) 07:07:45.36 (143641112)|HEAP_ALLOCATE|[32]|Bytes:41 07:07:45.36 (143794010)|FATAL_ERROR|System.NullPointerException: Attempt to de-reference a null object Trigger.UpdateApplicationStatusToEnrolled: line 32, column 1 07:07:45.36 (143808046)|FATAL_ERROR|System.NullPointerException: Attempt to de-reference a null object Trigger.UpdateApplicationStatusToEnrolled: line 32, column 1

Answer 1

You are getting that error because of this below line

List<vlocity_ins__Application__c> applicatioList =  strMap.get(acc.id);

strMap does not contain a key with the Account Id you are passing, hence it returns null which makes applicatioList variable null. And when you are trying to loop through this variable, you will get the null pointer exception which you are getting.

To fix this issue, you will have to check if the map contains the key, if not then initialize applicatioList to a new list and then loop through it.

Change your below line

List<vlocity_ins__Application__c> applicatioList =  strMap.get(acc.id);

to

List<vlocity_ins__Application__c> applicatioList =  strMap.containsKey(acc.id) ? strMap.get(acc.id) : new List<vlocity_ins__Application__c>();

Note : Ideally your strMap should contain all the Ids as keys, you will have to investigate by debugging the code and identify why is it that map does not contain those values.

Answer 2

I am not sure why you are getting that but few recommendations.

1. Remove system.debugs some time printing a list gives you null pointer exception.
2. strMap is initialized properly so it won't cause you an issue.

3. Please add if the condition to wrap your code

   if (accDetails <> NULL && accDetails.size()>0){ }

   if (strMap != null && strMap.size() >0){ }