Multithreading problem using System.out.print vs println

I have the following thread which simply prints a dot every 200ms: ``` public class Progress { private static boolean threadCanRun = true; private static Thread progressThread = new Thread(new Runnable() { public void run() { while (threadCanRun) { System.out.print('.'); System.out.flush(); try { progressThread.sleep(200); } catch (InterruptedException ex) {} } } }); public static void stop() { threadCanRun = false; progressThread.interrupt(); } public static void start() { if (!progressThread.isAlive()) { progressThread.start(); } else { threadCanRun = true; } } } ``` I start the thread with this code (for now): ``` System.out.println("Working."); Progress.start(); try { Thread.sleep(10000); //To be replaced with code that does work. } catch (InterruptedException ex) {} Progress.stop(); ``` What's really strange is this: If I use `System.out.println('.');` , the code works exactly as expected. (Apart from the fact that I don't want a new line each time). With `System.out.print('.');`, the code waits for ten seconds, and then shows the output. `System.out.println`: ``` Print dot, wait 200ms, print dot, wait 200ms etc... ``` `System.out.print`: ``` Wait 5000ms, Print all dots ``` What is happening, and what can I do to go around this behaviour? EDIT: I have also tried this: ``` private static synchronized void printDot() { System.err.print('.'); } ``` and printDot() instead of `System.out.print('.');` It still doesn't work. EDIT2: Interesting. This code works as expected: ``` System.out.print('.'); System.out.flush(); //Makes no difference with or without System.out.println(); ``` This doesn't: ``` System.err.print('.'); System.err.flush(); System.out.print('.'); System.out.flush(); ``` Solution: The issue was netbeans related. It worked fine when I run it as a jar file from java -jar. This is one of the most frustrating errors I have seen in my life. When I try to run this code with breakpoints in debug mode, everything works correctly.