(Count the occurrences of words in a text file) Rewrite Listing 21.9 to read the text from a text file. The text file is passed as a command-line argument. Words are delimited by whitespace characters, punctuation marks (, ; . : ?), quotation marks (' "), and parentheses. Count the words in a case-sensitive fashion (e.g., consider Good and good to be the same word). The words must start with a letter. Display the output of words in alphabetical order, with each word preceded by the number of times it occurs.
I ran my version of the program solution on its own Java source file to produce the following sample output:
C:\Users\......\Desktop>java CountOccurrenceOfWords CountOccurrenceOfWords.java
Display words and their count in ascending order of the words
1 a
1 alphabetical
1 an
2 and
3 args
2 as
1 ascending
1 catch
1 class
4 count
2 countoccurrenceofwords
1 create
1 display
1 else
3 entry
3 entryset
2 ex
1 exception
1 exit
1 file
2 filename
3 for
1 fullfilename
3 get
1 getkey
1 getvalue
1 hasnext
1 hold
5 i
3 if
2 import
2 in
3 input
2 int
1 io
3 java
6 key
3 length
2 line
1 main
3 map
1 matches
3 new
1 nextline
1 null
1 of
2 order
3 out
3 println
1 printstacktrace
2 public
2 put
2 scanner
1 set
1 split
1 static
5 string
4 system
2 the
1 their
1 to
1 tolowercase
2 tree
6 treemap
2 trim
1 try
1 util
1 value
1 void
1 while
9 words
C:\Users\......\Desktop>