因为还没有学网络，所以就在一个文件中寻找符合规则的邮箱

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

public class demo2 {

public static void main(String[] args)throws Exception { BufferedReader bufr=new BufferedReader(new FileReader(“e:\mail.txt”)); String line=null;

String regex=“[a-zA-Z0-9_]+@[a-zA-Z0-9_]+(\.[a-zA-Z]+){1,3}”; Pattern p=Pattern.compile(regex); while((line=bufr.readLine())!=null) { Matcher m=p.matcher(line); while(m.find()) { System.out.println(m.group()); } }

}

}