How to write a Quartz timer service that updates every 6 months? - mysql

Question

I want a Quartz timer service for the update code below. Every six months, all users' keys should be updated according to their creationDate:
//dataTypes are date only
List<User> allDbUsers=userRepository.findAll();
Date currDate=new Date();
final long DAY_IN_MILLIS = 1000 * 60 * 60 * 24;
for(User user:allDbUsers)
{
Date creationDate=user.getCreationDate();
String firstKey=user.getFirstKey();
Long diffInDays=(currDate.getTime()-creationDate.getTime())/DAY_IN_MILLIS;
if(diffInDays==180)
{
user.setSecondKey(firstKey);
user.setFirstKey("aH&#KK");
userRepository.saveAndFlush(user);
}
}

Answer 1

You can use Calendar for view diff between dates, for example:
Calendar currentDate = Calendar.getInstance();
Calendar sixMonthAfterCreation;
for (User user : allDbUsers) {
sixMonthAfterCreation = Calendar.getInstance()
sixMonthAfterCreation.setTime(user.getCreationDate());
sixMonthAfterCreation.add(Calendar.MONTH, 6);
String firstKey = user.getFirstKey();
if (currentDate.after(sixMonthAfterCreation)) {
user.setSecondKey(firstKey);
user.setFirstKey("aH&#KK");
userRepository.saveAndFlush(user);
}
}
or if you use java 8 you can convert you creation date to LocalDate and view diff.
If I right understand you, you want use Quartz Scheduler. I did not use it but I think you need implement org.quartz.Job, override execute method and write code for updating users in it.
For more information about Quartz Scheduler look this question
One clarification this code not for run scheduler, it code for method job.excecute(what job must do). Scheduler should run every midnight(for example), then every midnight will be called execute method which find all user for update and do it.