import java.io.BufferedReader;import java.io.File;import java.io.FileReader;import java.io.IOException;import java.util.ArrayList;import java.util.List;import java.util.regex.Matcher;import java.util.regex.Pattern;public class NetSpider {    public static void main(String[] args) throws IOException {                //将文件封装成File对象        File file = new File("mailTo.txt");                String regex = "\\w+@\\w+(\\.\\w+)+";                List<String> mailList = getMails(file,regex);                for(String mail:mailList){            System.out.println(mail);        }    }    public static List<String> getMails(File file,String regex) throws IOException {                        //1.先读取数据        BufferedReader bufr = new BufferedReader(new FileReader(file));                //2.将正则封装成对象        Pattern p = Pattern.compile(regex);                //3.定义list集合        List<String> list = new ArrayList<String>();                String line = null;        while((line=bufr.readLine())!=null){            Matcher m = p.matcher(line);                        while(m.find()){                list.add(m.group());            }                    }                return list;    }}