Thread class or Runnable interface ??

How can one decide whether to use Thread class or Runnable interface.
I know one scenario where if my class already extends another class, it has no choice but to implement the Runnable interface. Are there any other scenarios ?
Regards,
Mustang.

Suppose u want u'r class to act as a Thread i.e to be instantiated from other classes u extend u'r class from java.lang.Thread.
eg).performing a certain calculation.
If u r using threads within u'r class to do a certain job u implement runnable.
eg). using swing & displaying some animations.
This is what I know.
Happy middling with java.

Netharam.

Basically, if your class is a subclass of another class you can't extend thread so you'd have to use Runnable.

Its your choice. Typically one extends a class to add to its functionality though. Since their is no double inheritance, you can simply use Runnable, but it does not matter one bit.