提取匹配的表达式，电子邮件地址查找器

import java.util.regex.Matcher;

import java.util.regex.Pattern;
/*
 from 时 代 J a v a 公 众 号 
*/


public class Main {

  public static void main(String[] argv) {

    Pattern pattern = Pattern.compile(

        "([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]"

            + "{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))"

            + "([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)", Pattern.MULTILINE);


    Matcher matcher = pattern.matcher("");

    boolean matched = false;

    matcher.reset("asdfs@nowjava.com");

    while (matcher.find()) {

      System.out.println("\t" + matcher.group());


      matched = true;

    }