Could you please tell me how to find whether a class is mutable or immutable. If there is no way to set the member variables of the class (typically by calling the setXXX() methods) except in the constructor, the objects of that class are immutable.
Not quite true. See the article in the JavaRanch April Newsletter Mutable and Immutable Objects Point well taken. Of course, I didn't mentioned the fact that the object can be mutated indirectly by manipulating the reference to its internal mutable fileds. Nice article, David!