In fixed-delay execution, each execution is scheduled relative to * the actual execution time of the previous execution. If an execution * is delayed for any reason (such as garbage collection or other * background activity), subsequent executions will be delayed as well. * In the long run, the frequency of execution will generally be slightly * lower than the reciprocal of the specified period (assuming the system * clock underlying Object.wait(long) is accurate). * *
Fixed-delay execution is appropriate for recurring activities * that require "smoothness." In other words, it is appropriate for * activities where it is more important to keep the frequency accurate * in the short run than in the long run. This includes most animation * tasks, such as blinking a cursor at regular intervals. It also includes * tasks wherein regular activity is performed in response to human * input, such as automatically repeating a character as long as a key * is held down. * * @param task task to be scheduled. * @param delay delay in milliseconds before task is to be executed. * @param period time in milliseconds between successive task executions. * @throws IllegalArgumentException if delay is negative, or * delay + System.currentTimeMillis() is negative. * @throws IllegalStateException if task was already scheduled or * cancelled, timer was cancelled, or timer thread terminated. */ public void schedule(Runnable task, long delay, long period); /** * Schedules the specified task for repeated fixed-delay execution, * beginning at the specified time. Subsequent executions take place at * approximately regular intervals, separated by the specified period. * *
In fixed-delay execution, each execution is scheduled relative to * the actual execution time of the previous execution. If an execution * is delayed for any reason (such as garbage collection or other * background activity), subsequent executions will be delayed as well. * In the long run, the frequency of execution will generally be slightly * lower than the reciprocal of the specified period (assuming the system * clock underlying Object.wait(long) is accurate). * *
Fixed-delay execution is appropriate for recurring activities * that require "smoothness." In other words, it is appropriate for * activities where it is more important to keep the frequency accurate * in the short run than in the long run. This includes most animation * tasks, such as blinking a cursor at regular intervals. It also includes * tasks wherein regular activity is performed in response to human * input, such as automatically repeating a character as long as a key * is held down. * * @param task task to be scheduled. * @param firstTime First time at which task is to be executed. * @param period time in milliseconds between successive task executions. * @throws IllegalArgumentException if time.getTime() is negative. * @throws IllegalStateException if task was already scheduled or * cancelled, timer was cancelled, or timer thread terminated. */ public void schedule(Runnable task, Date firstTime, long period); /** * Schedules the specified task for repeated fixed-rate execution, * beginning after the specified delay. Subsequent executions take place * at approximately regular intervals, separated by the specified period. * *
In fixed-rate execution, each execution is scheduled relative to the * scheduled execution time of the initial execution. If an execution is * delayed for any reason (such as garbage collection or other background * activity), two or more executions will occur in rapid succession to * "catch up." In the long run, the frequency of execution will be * exactly the reciprocal of the specified period (assuming the system * clock underlying Object.wait(long) is accurate). * *
Fixed-rate execution is appropriate for recurring activities that * are sensitive to absolute time, such as ringing a chime every * hour on the hour, or running scheduled maintenance every day at a * particular time. It is also appropriate for for recurring activities * where the total time to perform a fixed number of executions is * important, such as a countdown timer that ticks once every second for * ten seconds. Finally, fixed-rate execution is appropriate for * scheduling multiple repeating timer tasks that must remain synchronized * with respect to one another. * * @param task task to be scheduled. * @param delay delay in milliseconds before task is to be executed. * @param period time in milliseconds between successive task executions. * @throws IllegalArgumentException if delay is negative, or * delay + System.currentTimeMillis() is negative. * @throws IllegalStateException if task was already scheduled or * cancelled, timer was cancelled, or timer thread terminated. */ public void scheduleAtFixedRate(Runnable task, long delay, long period); /** * Schedules the specified task for repeated fixed-rate execution, * beginning at the specified time. Subsequent executions take place at * approximately regular intervals, separated by the specified period. * *
In fixed-rate execution, each execution is scheduled relative to the * scheduled execution time of the initial execution. If an execution is * delayed for any reason (such as garbage collection or other background * activity), two or more executions will occur in rapid succession to * "catch up." In the long run, the frequency of execution will be * exactly the reciprocal of the specified period (assuming the system * clock underlying Object.wait(long) is accurate). * *
Fixed-rate execution is appropriate for recurring activities that * are sensitive to absolute time, such as ringing a chime every * hour on the hour, or running scheduled maintenance every day at a * particular time. It is also appropriate for for recurring activities * where the total time to perform a fixed number of executions is * important, such as a countdown timer that ticks once every second for * ten seconds. Finally, fixed-rate execution is appropriate for * scheduling multiple repeating timer tasks that must remain synchronized * with respect to one another. * * @param task task to be scheduled. * @param firstTime First time at which task is to be executed. * @param period time in milliseconds between successive task executions. * @throws IllegalArgumentException if time.getTime() is negative. * @throws IllegalStateException if task was already scheduled or * cancelled, timer was cancelled, or timer thread terminated. */ public void scheduleAtFixedRate(Runnable task, Date firstTime, long period); /** * Terminates this timer, discarding any currently scheduled tasks. * Does not interfere with a currently executing task (if it exists). * Once a timer has been terminated, its execution thread terminates * gracefully, and no more tasks may be scheduled on it. * *
Note that calling this method from within the run method of a * timer task that was invoked by this timer absolutely guarantees that * the ongoing task execution is the last task execution that will ever * be performed by this timer. * *
This method may be called repeatedly; the second and subsequent * calls have no effect. */ public void cancel(); /** * terminats task. If task is instance of TimerTask it's cancel method is invoked * otherwise TimerTask associated with task instance looked up in HashMap and its * cancel() method get invoked * @param task to be canceled */ public void cancelTask(Object task); }