Java String Tokens

Given a string ,s , matching the regular expression [A-Za-z !,?._'@]+, split the string into tokens. We define a token to be one or more consecutive English alphabetic letters. Then, print the number of tokens, followed by each token on a new line.

Note: You may find the String.split method helpful in completing this challenge.

Input Format

A single string, s.

Constraints

• 1 ≤ length of s ≤ 4*10⁵
• s is composed of any of the following: English alphabetic letters, blank spaces, exclamation points (!), commas (,), question marks (?), periods (.), underscores (_), apostrophes ('), and at symbols (@).

Output Format

On the first line, print an integer, n, denoting the number of tokens in string s (they do not need to be unique). Next, print each of the n tokens on a new line in the same order as they appear in input string s.

Sample Input

He is a very very good boy, isn't he?

Sample Output

10
He
is
a
very
very
good
boy
isn
t
he

Explanation

We consider a token to be a contiguous segment of alphabetic characters. There are a total of 10 such tokens in string s, and each token is printed in the same order in which it appears in string s.

Solution Implementation

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class JavaStringToken {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
       
        if (!sc.hasNext()){
            System.out.println(0);
        }else {
             String input=sc.nextLine();
            String[]a = input.trim().split("[ !,?._'@]+");
            ArrayList<String>listOfStrings =new ArrayList<String>(Arrays.asList(a));
            System.out.println(listOfStrings.size());
      
          for(String str:listOfStrings){
            System.out.println(str);
          }    
        }  
    }
}