Here you can find the source of isValidEmail(CharSequence target)
public static boolean isValidEmail(CharSequence target)
//package com.java2s; public class Main { public static boolean isValidEmail(CharSequence target) { if (target == null) { return false; } else {/*from w w w . jav a 2s . c o m*/ return android.util.Patterns.EMAIL_ADDRESS.matcher(target) .matches(); } } }