Data Abstraction and RMI in java

1)Can any 1 tell me what excatly the Data Abstraction concept in java is ???

2)Other thing i want to know is what is the use of stubs and skeleton in RMI
program. ???

Data abstraction is to hide something.... like in Java you are
associating the methods or in general words the behaviour of the
class which is hidden from the actual users. just by creating the
object of that class and calling the method you can get the desired
output. we can take an example of a car also. it has a break paddle,
irrespective of knowing hoe many joints and different parts
associated in that mechanism user simply applies pressure on paddle
and get the desired output i mean he is able to apply break. the
whole mechanism is working as a back end and its hidden from the
user of the car.

stubs and skeletons are used in the remote call in distributed
network. and they act as the proxy server and client for the
repective machine. in terms of RMI when we say that client is
communicating to the server, the actual communication happens
between the stub and skeleton. but in Java 2, skeleton does not
exist only stubs are there.

stubs is just a proxy at client side whereas skeleton is proxy at server side:-

view this for morw details:-

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