I have two objects 'Job Document History' and 'Job Position Transactional'. JPT is the master and JDH is child. In JDh i have field version. It should be unique for each relationship with JPT. I wrote trigger on JDH and trying to validate the duplicate values. Here the problem is Map is Case Sensitive. I want But i am

getting NullPointerException

when i am trying to enter opposite letters(like if 'A' already there but i given 'a').

Below is the my code:

trigger DuplicateVersion on Job_Document_History__c (before insert, before update) {
    Map<String, Job_Document_History__c> versionMap = new Map<String, Job_Document_History__c>();
    Set<string> jobPositionTran = new Set<string>();

    for (Job_Document_History__c jobDocHis : System.Trigger.new) {

        if ((jobDocHis.Version__c != null) && (System.Trigger.isInsert || (jobDocHis.Version__c != System.Trigger.oldMap.get(jobDocHis.Id).Version__c))) 

            if (versionMap.containsKey(jobDocHis.Version__c)) {
                jobDocHis.Version__c.addError('Another new document history has the same version Name.');
            } else {
                versionMap.put(jobDocHis.Version__c.toUpperCase(), jobDocHis);

    for (Job_Document_History__c jobDocHis : [SELECT Version__c FROM Job_Document_History__c WHERE Job_Position_Transactional__c IN :jobPositionTran and Version__c IN :versionMap.KeySet()]) {
        Job_Document_History__c newjobDocHis = versionMap.get(jobDocHis.Version__c.toUpperCase());
        newjobDocHis.Version__c.addError('This version is already exists.');
  • Basic idea would be add to map string in lower case and check that as well. F.e. versionMap.containsKey(jobDocHis.Version__c.toLowerCase())) or versionMap.put(jobDocHis.Version__c.toLowerCase(), jobDocHis);
    – kurunve
    Jan 19, 2016 at 14:36
  • Hi Kurunve, I tried this but it's not working. Jan 19, 2016 at 14:48
  • So, what do you want to achieve -- make map case insensitive?. And what kind of exception appears?
    – kurunve
    Jan 19, 2016 at 14:55
  • 2
    Why don't you just make the field unique case-insensitive instead of reinventing the wheel in apex?
    – Adrian Larson
    Jan 19, 2016 at 16:30

2 Answers 2


You can use toUpperCase() and covert the key to all in upper case.

versionMap.put(jobDocHis.Version__c.toUpperCase(), jobDocHis);
  • i tried this also but still it showing the error message. Error message is "Error: Invalid Data. Review all error messages below to correct your data. Apex trigger HR_DuplicateVersion caused an unexpected exception, contact your administrator: HR_DuplicateVersion: execution of BeforeUpdate caused by: System.NullPointerException: Attempt to de-reference a null object: Trigger.HR_DuplicateVersion: line 26, column 1". Line no 26 is "newjobDocHis.Version__c.addError('This version is already exists.');". Jan 19, 2016 at 14:50
  • @VijayKumar versionMap.get(jobDocHis.Version__c); -> you need to use here a versionMap.get(jobDocHis.Version__c.toUpperCase());.
    – kurunve
    Jan 19, 2016 at 14:59
  • @VijayKumar - that error means the key already exists thus your code is working as you expected. You asked for it to be case insensitive.
    – Eric
    Jan 19, 2016 at 15:10
  • 1
    @kurunve - Yup. I read it wrong - need coffee......
    – Eric
    Jan 19, 2016 at 15:15
  • 1
    I got the result as expected . Added .toUpperCase() in put() and get() methods. Updated latest code in the question. Jan 20, 2016 at 5:04

If you want to bypass the difference between 'A' and 'a' ,try to use containsIgnoreCase('string') method of String.By using this u can make the map key unique in ur case.

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