Find a string (or a line) in a txt File Java

Question

let's say I have a txt file containing:

john
dani
zack

the user will input a string, for example "omar" I want the program to search that txt file for the String "omar", if it doesn't exist, simply display "doesn't exist".

I tried the function String.endsWith() or String.startsWith(), but that of course displays "doesn't exist" 3 times.

I started java only 3 weeks ago, so I am a total newbie...please bear with me. thank you.

Answer 1

Just read this text file and put each word in to a List and you can check whether that List contains your word.

You can use Scanner scanner=new Scanner("FileNameWithPath"); to read file and you can try following to add words to List.

 List<String> list=new ArrayList<>();
 while(scanner.hasNextLine()){
     list.add(scanner.nextLine()); 

 }

Then check your word is there or not

if(list.contains("yourWord")){

  // found.
}else{
 // not found
}

BTW you can search directly in file too.

while(scanner.hasNextLine()){
     if("yourWord".equals(scanner.nextLine().trim())){
        // found
        break;
      }else{
       // not found

      }

 }

Answer 2

use String.contains(your search String) instead of String.endsWith() or String.startsWith()

eg

 str.contains("omar"); 

Answer 3

You can go other way around. Instead of printing 'does not exist', print 'exists' if match is found while traversing the file and break; If entire file is traversed and no match was found, only then go ahead and display 'does not exist'.

Also, use String.contains() in place of str.startsWith() or str.endsWith(). Contains check will search for a match in the entire string and not just at the start or end.

Hope it makes sense.