Scheduling Your Apex Classes Via Script

One of the most tedious tasks I face during deployment of my code to QA and Production orgs is the removing the scheduled classes and rescheduling them after the release  is completed.As the number of scheduled classes grows this becomes more and more difficult and prone to error as the possibility of  forgetting to reschedule some classes grows.

As I was on the look out  for a solution I found  that classes can be scheduled via apex and I tried writing a script to schedule my classes and to my luck It worked as i expected.As I thought there may be at least few of you who has faced the same issue I thought of sharing my code. Please note that this code may not be directly serve your purpose and will need some tweaking. But it will give you the basic idea of how classes can be scheduled via apex.


list<ApexClass> listClasses;
//create a string list and add the Names of classes you want to schedule
//please note that all of these classes must implement schedulable Interface
List<String> ClassesToBeScheduled = new List<String>(); ClassesToBeScheduled.add('FirstSchedule'); ClassesToBeScheduled.add('SecondSchedule'); ClassesToBeScheduled.add('ThirdSchedule'); ClassesToBeScheduled.add('FouthSchedule');

//query the salesforce apexclass object to get the records of classes you want to //schedule

for(ApexClass ac:[Select Id Name From ApexClass where Name IN:ClassesToBeScheduled]) { String className = ac.Name; String sch ='0 0 4 ? * * 2014'; // expersion specify how class is scheduled

//here the class is scheudled to run at 4.00 AM every day till the end of 2014

// you can learn all about schedule expressions here

Type t = Type.forName(className);

//schedule the class by passing 

//1.jobName - any string (here I use class name)

//2.schedule frequncy - string experssion specify when and hoe often each class //is run

//3.Instance of the class to be scheduled System.schedule(className, sch, (Schedulable)t.newInstance()); }

You can then run your script using developer console.