Check if string exists in text file-CodePudding

I'm trying to write a method, which checks if a given string exists in a .txt file, but it seems like my if/else statement isn't working correctly.

public void ChcekIfPasswordExsists(String check) throws FileNotFoundException{
    BufferedReader reader = new BufferedReader(new FileReader("Passwords.txt"));
    Scanner fileScanner = new Scanner(reader);
    while(fileScanner.hasNextLine()){
        final String line = fileScanner.next();
        if(line.contains(check)){
            System.out.println("Password for "   check   " already exsits");
            break;
        }
        else{
            System.out.println(check   " is usable");
            break;
        }        
    }
}

This is where I'm calling the method:

System.out.println("Enter the name of the app or website,\nwhere password is going to be use:");
useCase = s.nextLine();
 ChcekIfPasswordExsists(useCase);

I have looked at countless other posts with no effect. No matter what, it seems like the code skips the "if" statement and directly jumps to the "else" statement.

CodePudding user response：

The logic of your while loop should be to iterate over all lines in the file until either you find a match or you hit the end of the file. Consider this version:

public void ChcekIfPasswordExsists(String check) throws FileNotFoundException {
    BufferedReader reader = new BufferedReader(new FileReader("Passwords.txt"));
    Scanner fileScanner = new Scanner(reader);
    boolean flag = false;
    while (fileScanner.hasNextLine()) {
        final String line = fileScanner.next();
        if (line.contains(check)) {
            flag = true;
            break;
        }
    }

    if (flag) {
        System.out.println("Password for "   check   " already exsits");
    }
    else {
        System.out.println(check   " is usable");
    }
}

Also, I might be inclined to change the method signature to return a boolean value (true/false). Based on that return value, you can display to the console the message you want.

Side note: If you are actually storing cleartext passwords in a text file, then stop doing that immediately. It is a security hole. Instead, setup a proper database and only store an irreversible hash of the passwords.