Scheduling alternative to Timer

Question

Hi,
I have a server instance which runs on JVM 1.2. I can't upgarde it to JVM 1.3 and above too. So I cannot implement scheduling using the Timer class.
What are the other options I have to implement a scheduling task in java . Let say i want to print "Hello JAVA" every day.
Thanks
jigo

Answer 1

Let say i want to print "Hello JAVA" every day.
new Thread() {
    public void run() {
        while (true) {
            try {
                // The "24" here is really "24L" to avoid overflow. The forum
                // software in its infinite wisdom clips off the "L".
                Thread.sleep(24L * 60 * 60 * 1000);
                System.out.println("rhubarb");
            } catch (Throwable e) {
                ...log the exception...
}.start();If you need to do it at e.g. midnight: calculate the time until the next midnight and sleep that amount. Oh, what the heck:
    public static void sleepModulo(long milliseconds, long minimum_sleep)
        long now = System.currentTimeMillis();
        long then = now / milliseconds * milliseconds + milliseconds;
        long sleep = then - now;
        if (sleep < minimum_sleep)
            sleep += milliseconds;
        if (sleep == 0)
            return;
        try {
            Thread.sleep(sleep);
        } catch (InterruptedException e) {
            // ignore
    }Your operating system might not like if you start hundreds of threads. So if you have hundreds of tasks you may want to write a Timer class yourself. Or google, someone has probably done one already. If you just have a few tasks you can use individual threads.