CODEWITHSUNDEEP
javatimer
maxi
maxi

Reputation: 9

Build a Java reminder for a web project

I have a requirement for a web project to build a reminder that display a message for the input date and time. I don't want to use any plugins or jar files. I came up with the code and there is an error in timer.schedule(task,date);

I'm also new to java and don't know if this is the right approach.

Code:

public String reminder(Model model, HttpServletRequest req, HttpServletResponse res) throws ParseException
{

    String myDate = "2012-06-09 17:43:20";

    DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    Date date = (Date)formatter.parse(myDate);

    TimerTask task = YoTimes(model);
    Timer timer = new Timer();
    timer.schedule(task,date);

    return "/view";
}

private TimerTask YoTimes(Model model) 
{
    model.addAttribute("timerMsg", "Yo Timer");
    return null;
}

EDIT

Stacktrace:

ERROR:java.lang.NullPointerException 
    at java.util.Timer.sched(Unknown Source) 
    at java.util.Timer.schedule(Unknown Source)

Upvotes: 0

Views: 1206

Answers (2)

Alexis Pigeon
Alexis Pigeon

Reputation: 7522

Your YoTimes method returns null. It should return an instance of java.util.TimerTask, so that you can pass it to Timer#schedule(TimerTask, Date).

The edited yoTimes method (note that as a best practice / convention, Java methods should start with a lowercase character):

private TimerTask yoTimes(Model model) {
    model.addAttribute("timerMsg", "Yo Timer");
    return new MyTimerTask();
}

The newly created MyTimerTask class:

public class MyTimerTask extends TimerTask {
    public void run() {
        // Whatever the task should be
    }
}

Upvotes: 2

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285460

private TimerTask YoTimes(Model model) 
{
    model.addAttribute("timerMsg", "Yo Timer");
    return null; // ************
}

Please look at what you're returning here!

No surprise then that this will cause a NPE. Perhaps you want to return an actual TimerTask object. ;-)

So instead create and return your TimerTask:

private TimerTask YoTimes(final Model model) 
{
    model.addAttribute("timerMsg", "Yo Timer");
    return new TimerTask() {
       public void run() {
          // whatever code you want called by the timer
       }
    };
}

Upvotes: 2

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