Hi,
I have schedule my class and i want to send the notification when schedule job failes. Here is the code which i have implemented:

global class CaseAssignmentScheduler00 implements Schedulable  
{
    public static dateTime dt=System.now().addMinutes(5);
    public static String Csec=String.valueof(dt.second());
    public static String Cmin=String.valueof(dt.minute());
    public static String Chr=String.valueof(dt.hour());
    public static String Cday=String.valueof(dt.day());
    public static String Cmonth=String.valueof(dt.month());
    public static String CYear=String.valueof(dt.Year());
    public static String SchTimer= Csec+' '+Cmin+' '+Chr+' '+Cday+' '+Cmonth+' ? '+CYear;
    list<string> emailaddress = new list<string>(); 
    public static integer count=0;
    global void execute(SchedulableContext SC)     
    {
       
        try{
            CaseRoundRobinAssignmentController.CaseAssignmentFromQueue();
            doScheduling();
            
        }
        catch(exception e){
    }
    
    public void doScheduling(){
        system.debug('*************SchTimer:'+SchTimer);
        CaseAssignmentScheduler00 cas = new CaseAssignmentScheduler00();
        system.schedule('CaseAssignmentScheduler00: Assigning Cases from Queue to Active Users at '+System.now().format(), SchTimer, cas);
        //checkJobStatus();     
            
            for( CronTrigger c:[Select c.TimesTriggered, c.TimeZoneSidKey, c.State, c.StartTime, c.PreviousFireTime, c.OwnerId, c.NextFireTime, c.LastModifiedById, c.Id, c.EndTime, c.CronExpression, c.CreatedDate, c.CreatedById From CronTrigger c where c.NextFireTime=null  AND c.State='DELETED' Limit 100]){
                System.abortJob(c.id);
            }
    }
    
    /****** Send email notification to Admin if Job fails*****/
    public void checkJobStatus(){
        // Featch the Email ID from custom setting
        for(Case_Scheduler_Email__c Em : Case_Scheduler_Email__c.getAll().values()){
                             emailaddress.add(Em.Email__c);      
        }
        
        for(AsyncApexJob aj: [Select Id, Status, NumberOfErrors, JobItemsProcessed,TotalJobItems, ExtendedStatus, createdDate ,ApexClassID, MethodName
                from AsyncApexJob where Status = 'Failed' LIMIT 1])
                { 
                   
                    {
                            
                        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
                        mail.setToAddresses(emailaddress);
                        mail.setSenderDisplayName('Case Scheduler Job');
                        mail.setSubject('Case Scheduler Job Fails');
                        mail.setHtmlBody('The Scheduled batch Apex job got failed. Please check the schedule job and take the necessary action. ' +'Here is the Error Message: ' + aj.ExtendedStatus);
    
                        Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
                   }
               }
        }
}
Seem this code is not working. can any one help me on this ?