Permanent While loop Java

Question

I have been struggling with my while loop and was wondering if you guys can see the fault in my logic.

The concept of the project

Creating a machine that will permanently loop through a bunch of code for the rest of its existence. Basically I am making an automatic cat feeder that will dispense food at certain times during the day. THAT IS WHY THE LOOP MUST BE PERMANENT.

Here is my basic code so far:

    DateFormat dateFormat = new SimpleDateFormat("HH:mm");                                                                                    // 1.

    Calendar cal = Calendar.getInstance();                                                                                                                      // 2.

    String CurrentTime  = dateFormat.format(cal.getTime());                                                                                 // 3. 

    jTextArea2.setText(CurrentTime);


    String FeedTimeMorning              = "06:00";
    String FeedTimeSnack                = "19:07";
    String FeedTimeMidday               = "12:30";




    boolean TempFeed = false;


     while(TempFeed=false)

     {

     if (FeedTimeMorning.equals(CurrentTime)) { txaOne.setText("FeedCats"+" " +CurrentTime);}


     if (FeedTimeSnack.equals(CurrentTime)){txaOne.setText("FeedCats"+" " +CurrentTime);}


     if(FeedTimeMidday.equals(CurrentTime)){txaOne.setText("FeedCats"+" " +CurrentTime);}

When it comes to the designated time the text "Feed Cats " does not appear.

Any help would be appreciated.

If it has to be permanent then why not just loop infinitely? `while(true)` — Ceelos, Mar 15 '16 at 17:20
Please read up on [Java naming conventions](http://www.oracle.com/technetwork/java/codeconventions-135099.html). It'll make your code much more readable. — Marv, Mar 15 '16 at 17:24
Use `while(true)`. Writing `while(TempFeed==false)` is a quiet plea for re-education on coding standards. — erickson, Mar 15 '16 at 17:25
Better to use sleep. Calculate time till next cat feed, then use sleep. Your loop will chew up a lot of CPU cycles just checking the time very often — Paulus, Mar 15 '16 at 17:28
Paulus, Haven't used the function. But what I can understand is, I can tell the sleep function to check lets say every half hour if the current time is this of the feeding time? — The Noobie Coder, Mar 15 '16 at 17:31
@TheNoobieCoder Even better (for that) might be a [`Timer`](https://docs.oracle.com/javase/8/docs/api/java/util/Timer.html). — Elliott Frisch, Mar 15 '16 at 17:35

score 4 · Accepted Answer · answered Mar 15 '16 at 17:21

4

One equals (=) is assignment while two (==) is equality, this

while(TempFeed=false)

should be one of

while(TempFeed==false)

or the shorter boolean negation (omitting the = entirely) like

while(!TempFeed)

With one = it assigns false to TempFeed and evaluates to false (which means the loop is never entered).

answered Mar 15 '16 at 17:21

Elliott Frisch

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@erickson Think I might have asked something similar to a question with an answer, Still appreciate the answers from everyone – The Noobie Coder Mar 15 '16 at 17:38
@TheNoobieCoder I hope my answer helped; you might also have better luck with cron or (if you must use Java) [quartz scheduler](https://quartz-scheduler.org/). – Elliott Frisch Mar 15 '16 at 17:40

Permanent While loop Java

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