Text in Files (search)

package file;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main implements Runnable
{
    public static void main(String[] args) {

        File[] fileList;
        File F = new File("D:\\level2\\");

        fileList = F.listFiles();

        String s = "";
        Scanner in = null;

        String EMAIL_PATTERN = ("\\w+([\\.-]?\\w+)*@\\w+([\\.-]?\\w+)*(\\.\\w{2,4})+");
        Pattern pattern = Pattern.compile(EMAIL_PATTERN);

        for (int i = 0; i < fileList.length; i++){
            if (fileList[i].isFile())
                System.out.println(String.valueOf(i) + " - " + fileList[i].getName()); //вывод имени файла в директории

            //run(fileList[i]); //создание потока
            //pattern(String.valueOf(fileList[i]));
            //String.valueOf(fileList[i]);

            try {
                in = new Scanner(fileList[i]);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            while (in.hasNext()) {
                s += in.nextLine() + "\r\n"; //создание массива строк
                Matcher m = pattern.matcher(s);
                if (m.matches())
                    System.out.println ("e-mail MATCH!");
                else
                    System.out.println ("NO e-mail");
            }
            in.close();
            //pattern(String.valueOf(fileList[i]));

        }

        System.out.println(s); //вывод на экран ранее созданных (считанных) строк из файлов.
    }
    public static void run(File file) {
        Thread th = new Thread();
        System.out.println("Создан поток"); //Проверка создания потока
    }

    public void run() {

    }

/*
    public static boolean pattern(String s){
        String EMAIL_PATTERN = ("\\w+([\\.-]?\\w+)*@\\w+([\\.-]?\\w+)*(\\.\\w{2,4})+");

        Pattern pattern = Pattern.compile(EMAIL_PATTERN);
        Matcher m = pattern.matcher(s);

        if (m.matches ()) System.out.println ("e-mail MATCH!");
        else System.out.println ("e-mail NO match");
//----------------
       Pattern pattern1 = Pattern.compile ("\\d\\d:\\d\\d");
        Matcher m1 = pattern1.matcher(s);

        if (m1.matches ()) System.out.println ("time match");
        else System.out.println ("time no match");
//------------------
        Pattern pattern2 = Pattern.compile ("\\d\\d\\.\\d\\d\\.\\d\\d\\d\\d");
        Matcher m2 = pattern2.matcher(s);

        if (m2.matches ()) System.out.println ("date match");
        else System.out.println ("date no match");
//---------------
        Pattern pattern3 = Pattern.compile("[A-Za-z]+");
        Matcher m3 = pattern3.matcher(s);

        if (m3.matches ()) System.out.println ("name match");
        else System.out.println ("name no match");
      return Boolean.parseBoolean(s);
    }
    */
}