Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {

    public static void main(String[] args) {
        System.out.println(getFirstWord("this is a test"));
    }

    /**
     * Get the first word (pure alphabet word) from the String
     * 
     * @param source
     *          the string where the first word is to be extracted
     * @return the extracted first word or null if there is no first word
     */
    public static String getFirstWord(String source) {
        if (source == null) {
            return null;
        }

        source = source.trim();

        if (source.isEmpty()) {
            return null;
        }

        if (containsSpace(source)) {

            final int FIRST_WORD_GROUP = 1;
            String firstWordRegex = "^[^A-z]*([A-z]+)";
            Pattern pattern = Pattern.compile(firstWordRegex);
            Matcher matcher = pattern.matcher(source);
            if (matcher.find()) {
                return matcher.group(FIRST_WORD_GROUP);
            } else {
                return null;
            }
        } else {
            return source;
        }
    }

    private static boolean containsSpace(String source) {
        return source.contains(" ");
    }
}