JAVA - how to ignore all words that contains non-alphabetical letters

jeispyun :

My program reads txt file with Scanner and save each and every words in it in ArrayList, word by word, by using Scanner.next(). In here, any words that contains non-alphabetical letters should be ignored, meaning should not be counted as word at all(not replacing them). For example: "U2", "data-based", or "hello!" should not be counted at all.

I could make it to read all words and save it to ArrayList, but I am stuck with ignoring words containing non-letter element.

This is my partial code:

public static void main(String[] args) {
    ArrayList<Word> wordList = new ArrayList<Word>();
    int wordCount = 0;
    Scanner input;

    try {
        System.out.println("Enter the file name with extension: ");
        input = new Scanner(System.in);
        File file = new File(input.nextLine());
        input.close();
        input = new Scanner(file);
        while(input.hasNext())
        {
            Word w = new Word(input.next().toLowerCase()); //should be case-insensitive
            if(!wordList.contains(w)) //equals method overriden in Word class
            wordList.add(w);
            else 
            {
                wordList.get(wordList.indexOf(w)).addCount();
            }
            wordCount++;
        }
        input.close();

Word class is defined by me and is just a simple class with attributes of word(String) and count(int). equals() method was defined.

I think regex would be the solution for this, but since I am not sure how to define "non-alphabetical" in regex(I have no knowledge of regex) I can't define solid range..

Any help would be appreciated!

Nicholas K :

You can use the regex ^[a-zA-Z]*$ to match only alphabets. Use this before adding to your ArrayList.

Now you can use the .matches() of the String class to check if it contains only alphabets. An eg :

String str = "asd";
if (str.matches(^[a-zA-Z]*$)) {
   // only alphabets
} else {
   // something else
}