Beginner Programmer: Timer

Question

I'm pretty new to Java (or to any programming language for that matter), and I was wondering how to make a timer, and how hard it is to make one. In my programming class at school, all our programs were pretty small, and they only ran in the compiler in Dr. Java. Well I'm making a small game, and what I want is a System.out.println("!"); or something like that, and then a readLine(); where the user types what is printed (The exclamation mark). The goal I want requires some sort of timer, that counts to 2 seconds or something. When the timer is up, it will skip the Textbox that pops up, and display "You were too slow!", and if they type it quickly enough, the game prints "You beat the timer!", and continue with the game.
Basically:
System.out.println("!");
//Timer starts
in = br.readLine(); //'in' being a String to hold input, and 'br' being the BufferedReader. If timer runs out, skip the textbox, or just send 'in' the wring answer, continuing the game
//Timer stops
if (in.equals("!") && //Timer was less than 2 seconds) {
System.out.println("You did it!"); }
else {
System.out.println("You were too slow!");  }Is this possible? If so, can someone post the code for it, or explain how to make it? I REALLY want this to work!!!
Thanks in advanced!

Answer 1

Dr.Awesome wrote:
Ok, I ran the program and it works, but it won't stop when I press Ctrl+C, was that just an example or was it really supposed to stop? It wasn't actually suppose to stop if you press Ctrl+C. You would have to add some sort of key listener for that to happen. At this point, that's a probably a little too complex.
Also, just so I can fully understand this, what does .printf do? I've been taught .println and .print already. To me it looks like it has the same effect as .print...Printf basically prints a formatted string. By "formatted string" I mean that you can do things like left justification, right justification, show only 3 decimals, ect.. Just stick with print and println for now.
Next, I recognize the 'while' but we've only used it after a 'do'. Does it just repeat the timer.schedule?The while loop keeps the program (and more specifically the Java Virtual Machine) from exiting. It's kind of awkward example for a person new to java, since they would have to understand a little about Threads to see its purpose. If you don't know what threads are, then I'm not sure you should be trying to delve into the Timer class.
A 'while' loop is pretty much the same thing as a do-while loop ( link ) but in the case of the do-while loop you necessarily do at least one iteration before checking the condition in the while statement.
Lastly, what does the 'true' represent in the 'while'? Does it change to false once I press Ctrl+C/ override it?If you press the link above you will see that a while loop evaluates an expression like while(i < 5) . The expression i<5 is a true or false statement. That is, it evaluates to a boolean. Sometimes it may be true, sometimes it may be false (at which point the loop stops).
The value "true" is basically an expression that's always true (specifically it is a boolean literal). So if I write something like while(true) then I'm making the loop forever ... well loop.
So when he includes
while(true);at the end of the main method, it's equivalent to
while(true) {
   //this will forever loop
//i won't ever get down here