import static org.junit.Assert.fail;

import java.io$.$FileInputStream;

import java.io$.$FileNotFoundException;

import java.util.ArrayList;

import java.util.Scanner;

public class PatternMatcher $\{$

public static void main$($String$[]$ args$)\{$

Scanner scnr $=$ new Scanner$($System$.$in$)$;

String fileName;

ArrayList wordList;

System.out.print$("$Enter a file name to search in: $")$;

fileName $=$ scnr$.$nextLine$()$;

try $\{$

wordList $=$ getWordList$($fileName$)$;

System.out.println$("$File read successfully, initiating pattern matcher..."$)$;

$\}$ catch $($FileNotFoundException e$)\{$

System.out.println$("$Error: File not found, exiting..."$)$;

scnr$.$close$()$;

return;

$\}$

while $($true$)\{$

System.out.print$("$Enter a pattern to match $($or press Enter to exit$)$: $")$;

String pattern $=$ scnr$.$nextLine$().$trim$()$;

if $($pattern$.$isEmpty$())\{$

System.out.println$("$Exiting$...")$;

break;

$\}$

ArrayList matches $=$ getMatches$($wordList$,$ pattern$)$;

System.out.println$("$Matches for pattern $\backslash ""+$ pattern $+"\backslash "$: $"+$ matches$)$;

$\}$

scnr$.$close$()$;

$\}$

public static ArrayList getWordList$($String filename$)$ throws FileNotFoundException $\{$

ArrayList wordList $=$ new ArrayList$<>()$;

FileInputStream file $=$ new FileInputStream$($filename$)$;

Scanner fileScnr $=$ new Scanner$($file$)$;

while $($fileScnr$.$hasNext$())\{$

String newWord $=$ fileScnr.next$().$trim$()$;

if $(!$newWord.isEmpty$())\{$

wordList.add$($newWord$)$;

$\}$

$\}$

fileScnr.close$()$;

return wordList;

$\}$

public static boolean isMatchAtIndex$($String word, String pattern, int index$)\{$

if $($index $<0||$ index $>=$ word.length$()||$ index $>=$ pattern.length$())\{$

return false;

$\}$

char patternChar $=$ pattern.charAt$($index$)$;

char wordChar $=$ word.charAt$($index$)$;

return patternChar $==\text{'}\_\text{'}||$ patternChar $==$ wordChar;

$\}$

public static boolean isMatch$($String word, String pattern$)\{$

if $($word$.$length$()!=$ pattern.length$())\{$

return false;

$\}$

for $($int i $=0$; i $<$ word.length$()$; i$++)\{$

if $(!$isMatchAtIndex$($word$,$ pattern, i$))\{$

return false;

$\}$

$\}$

return true;

$\}$

public static ArrayList getMatches$($ArrayList wordList, String pattern$)\{$

ArrayList matches $=$ new ArrayList$<>()$;

for $($String word : wordList$)\{$

if $($isMatch$($word$,$ pattern$))\{$

matches.add$($word$)$;

$\}$

$\}$

return matches;

$\}$

$\}$

FAIL $-$ Program did not print out correct list of words to match pattern.

given a wordList taken from words.txt

and the input pattern : "words.txt

$\_\_$tto

m$\_$th$\_\_$

$\_$x$\_$y$\_$z

$"$

Expected :

Enter a file name to search in : File read successfully, initiating pattern matcher...

Enter a pattern to match $($or press Enter to exit$)$: $[$motto$,$ petto, sotto, tutto$]$

Enter a pattern to match $($or press Enter to exit$)$: $[$methyl$]$

Enter a pattern to match $($or press Enter to exit$)$: $[]$

Enter a pattern to match $($or press Enter to exit$)$: Exiting...

but got :

Enter a file name to search in: File read successfully, initiating pattern matcher...

Enter a pattern to match $($or press Enter to exit$)$: Matches for pattern $"\_\_$tto": $[$motto$,$ petto, sotto, tutto$]$

Enter a pattern to match $($or press Enter to exit$)$: Matches for pattern $"$m$\_$th$\_\_"$: $[$methyl$]$

Enter a pattern to match $($or press Enter to exit$)$: Matches for pattern $"\_$x$\_$y$\_$z$"$: $[]$

Enter a pattern to match $($or press Enter to exit$)$: Exiting...

Test your code manually to identify and correct any errors.

FAIL $-$ Program did not print out correct list of words to match pattern.

given a wordList taken from words.txt

and the input pattern : "nonexistant.txt

$\_\_$tto

m$\_$th$\_\_$

$\_$x$\_$y$\_$z

$"$

Expected :

Enter a file name to search in : Error: File not found, exiting...

but got :

Enter a file name to search in: Error: File not found, exiting...

Test your code manually to identify and correct any errors.