Java threads
- 1. Thread Objects Each thread is associated with an instance of the class Thread.
- 2. Defining and Starting a Thread Three ways ● Provide a Runnable object. ● Subclass Thread. ● Using Executor Interface
- 3. public interface Runnable The Runnable interface should be implemented by any class whose instances are intended to be executed by a thread. The class must define a method of no arguments called run. void run( ) starting the thread causes the object's run method to be called in that separately executing thread.
- 4. Hello from a thread!
- 5. Using Inner class Hello from a thread!
- 6. Extending Thread class The Thread class itself implements Runnable, though its run method does nothing. An application can subclass Thread, providing its own implementation of run method.
- 7. Hello from a thread!
- 8. Using Inner class Hello from a thread!
- 10. Runnable vs. Thread ● Runnable object, is more general, because the Runnable object can subclass a class other than Thread. ● Sub-classing Thread is easier to use in simple applications or Testing code , but is limited by the fact that your task class must be a descendant of Thread
- 11. Thread scheduling How each task will be run, including details of thread use, scheduling, etc. This code need to be seprated from the instantiating thread class.
- 12. a way of decoupling task submission from the mechanics of how each task will be run. Task submission The Executor will provide the mechanics of how Task will be executed.
- 13. java.util.concurrent.Executor An object that executes submitted Runnable tasks.
- 15. The best approach is to separate the Runnable from the execution task and it is compulsory for large-scale applications.
- 16. Pausing Execution with Sleep Thread.sleep causes the current thread to suspend execution for a specified period. This is an efficient means of making processor time available to the other threads of an application.
- 17. Quotes.java prints one Quote, pauses for 1 second, prints next Quote, ...
- 18. Interrupted Exception sleep throws Interrupted Exception when another thread interrupts the current thread while sleep is active.
- 19. Two overloaded versions of sleep are provided ● sleep time = millisecond ● sleep time = nanosecond However, these sleep times are not guaranteed to be precise, because they are limited by the facilities provided by the underlying OS.