Java 邮箱判断 正则表达式

import java.util.Scanner;

public final class EmailCheck
{
public static boolean checkEmail(String email)
{
String regex1 = "[a-zA-Z]+[a-zA-Z0-9_]*@[a-zA-Z0-9]+[.][a-zA-Z0-9]+";
//字母开头，@后加字母或数字，后面加点，后面字母或数字
String regex2 = "[a-zA-Z]+[a-zA-Z0-9_]*@[a-zA-Z0-9]+[.][a-zA-Z0-9]+[.][a-zA-Z0-9]+";
//..........在regex1基础上，后面加.和其他字母组成的后缀

if(email.matches(regex1) || email.matches(regex2))
{
System.out.println("合法邮箱地址");
return true;
}
else
{
System.out.println("不合法邮箱地址");
return false;
}
}
public static boolean checkabc(String email)
{
//判断是否包含 某字符串，判断是某个网站的邮箱
if(email.indexOf("@abc.com") > -1)
{
System.out.println("abc");
return true;
}
else
{
System.out.println("非abc");
return false;
}
}
}

class Entry
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
String email = input.next();
EmailCheck.checkEmail(email);
EmailCheck.checkabc(email);
}
}