Write a command line application Problem2.java that indexes the words contained in a text file. Your program should go through the input file line by line. For each line, it extracts each word, and insert that word, along with it's line numberinto an AVL tree. Each element of the AVL tree should contain a unique word and a linked list of line numbers where that word occurs.

Write the method public void indexWord(String word, int line) that adds an occurrence of the word word in line line. If a word already exists in the AVL Tree, simply add the new line number to the existing node. If a word appears on the same line twice, it should only have one entry in the list for that line.

Write the method public List getLinesForWord(String word) that looks up a word and returns a list of lines in which it occurs.

Write the method public void printIndex() the prints out each unique word that is stored in the Avl tree along with a list of line numbers in which that word appears.