Runnable

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 .This interface is designed to provide a common protocol for objects that wish to execute code while they are active. For example,  Runnable  is implemented by class  Thread . Being active simply means that a thread has been started and has not yet been stopped.

In addition,  Runnable  provides the means for a class to be active while not subclassing  Thread . A class that implements  Runnable  can run without subclassing  Thread  by instantiating a  Thread  instance and passing itself in as the target. In most cases, the  Runnable  interface should be used if you are only planning to override the  run()  method and no other  Thread  methods. This is important because classes should not be subclassed unless the programmer intends on modifying or enhancing the fundamental behavior of the class.