Which method should a non abstract class implementing Runnable interface implement
Improve Article Show Save Article java.lang.Runnable is an interface that is to be implemented by a class whose instances are intended to be executed by a thread. There are two ways to start a new Thread – Subclass Thread and implement Runnable. There is no need of subclassing a Thread when a task can be done by overriding only run() method of Runnable. Steps to create a new thread using Runnable
Example 1 java
Output: Main thread is- main Thread-0, executing run() method! The output shows two active threads in the program – main thread and Thread-0, main method is executed by the Main thread but invoking the start on RunnableImpl creates and starts a new thread – Thread-0. What happens when Runnable encounters an exception ? Runnable can’t throw checked exception but RuntimeException can be thrown from the run(). Uncaught exceptions are handled by the exception handler of the thread, if JVM can’t handle or catch exceptions, it prints the stack trace and terminates the flow. Example 2 java
Output: Thread-0, executing run() method! Must catch here! java.io.FileNotFoundException at RunnableDemo$RunnableImpl.run(RunnableDemo.java:25) at java.lang.Thread.run(Thread.java:745) Exception in thread "Thread-0" java.lang.ArithmeticException: / by zero at RunnableDemo$RunnableImpl.run(RunnableDemo.java:31) at java.lang.Thread.run(Thread.java:745) The output shows that Runnable can’t throw checked exceptions, FileNotFoundException in this case, to the callers, it must handle checked exceptions in the run() but RuntimeExceptions (thrown or auto-generated) are handled by the JVM automatically. Which of the methods should be implemented if any class implements the runnable interface?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 . This interface is designed to provide a common protocol for objects that wish to execute code while they are active.
Which method should a nonAn abstract method must be implemented in all non-abstract classes using the override keyword.
Which method is implemented runnable interface?The runnable interface implementation uses the code inside the run() method and executes it on a concurrent thread. You can either invoke class, create new variables, or call the action in the run() method to implement the runnable interface in Java.
Can a nonInterfaces can not have non-abstract Methods while abstract Classes can. A Class can implement more than one Interface while it can extend only one Class.
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