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Q) Explain about some methods?

A)
getClass() :
                        Method returns java.long.class type. It represents the runtime context of the class from which the object is created.

clone() :
                        Method is used to create an exact copy of that object.

hashCode() :
                        Method returns an integer. That represents the hash code of object. JVM produces hash code based on the object address.
toString() :
                        Method is meant for textual representation.
equals() :
                        Method is used to compare two objects.
finalize() :
                        Method is almost not implementing in a class. Hypothetically it can be used to release the recourses allocated to the object. If needed we can make the object reachable by assigning the object address to the reference variable in the finalize() methods.
finalize() is called before garbage collection.

wait() :
                        Method suspense a thread acting upon a synchronize object.
notify() :
                        Transits a thread from blocked state to active state which is suspended by calling wait(). This method is also can be called only on the synchronized object.

notifyAll() :
                        It wakes up all the suspended threads which are blocked through wait() method. This method is also can be called only on the synchronized object.

Note:
the above 3 methods are mostly used in interThread communication.

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