Here you can find the source of isEmail(String email)
public static boolean isEmail(String email)
//package com.java2s; /*/*ww w . j av a 2s. com*/ * Copyright 2002-2007 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.regex.Pattern; public class Main { private static Pattern emailPattern; public static boolean isEmail(String email) { if (emailPattern == null) { String regStr = "\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*"; emailPattern = Pattern.compile(regStr); } return emailPattern.matcher(email).find(); } }