Instructions:

$1.$ The first task is to create a watcher that will monitor changes to a folder$/$directory$.$ You

need to monitor for the following three kinds of changes: addition of a file$/$directory$,$

deletion of a file$/$directory and changes to a file $($e$.$g$.,$ file size changes$).$ Directory can

contain other directories and files.

The watcher can be considered as a subject in the observer design pattern. You need to

implement one observer that will print a short description of the changes when get notified

$($example can be like: File A is added$).$ Your program should be written in Java. You need

to use the java.util.Observable class and java.util.Observer interface to complete the

program. $($Total Marks: $10)$

$2.$ Your second task is to apply the iterator design pattern to traverse through the nodes of a

binary search tree and print node information. Each node in the tree represents a student

record, consisting of first name, last name, department and student id $($represented as an

integer number and use that as a key$).$ Your program should visit the nodes in preorder,

inorder or post order traversal mechanism. Thus, your program should create three

different iterators to traverse the tree in three different ways. Your program should be

written in Java and you need to use java.util.Iterator interface to complete the program

$($Total Marks: $10)$