java对email邮箱的真实、有效性验证的例子

三种验证邮箱有效性的方式：
方式1：
public static boolean checkEmail(String email) {
    if (!email.matches("[\\w\\.\\-]+@([\\w\\-]+\\.)+[\\w\\-]+")) {
        return false;
    }
    String host = "";
    String hostName = email.split("@")[1];
    Record[] result = null;
    SMTPClient client = new SMTPClient();
    try {
        // 查找MX记录
        Lookup lookup = new Lookup(hostName, Type.MX);
        lookup.run();
        if (lookup.getResult() != Lookup.SUCCESSFUL) {
            return false;
        } else {
            result = lookup.getAnswers();
        }
        // 连接到邮箱服务器
        for (int i = 0; i < result.length; i++) {
            host = result[i].getAdditionalName().toString();
            client.connect(host);
            if (!SMTPReply.isPositiveCompletion(client.getReplyCode())) {
                client.disconnect();
                continue;
            } else {
                break;
            }
        }
        //以下2项自己填写快速的，有效的邮箱
        client.login("163.com");
        client.setSender("sxgkwei@163.com");
        client.addRecipient(email);
        if (250 == client.getReplyCode()) {
            return true;
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            client.disconnect();
        } catch (IOException e) {
        }
    }
    return false;
}
此方式需要的jar支持：commons-net-2.2.jar，dnsjava-2.1.1.jar
方式2：
 public static boolean checkEmail(String email) throws Exception {
  if (!email.matches("[\\w\\.\\-]+@([\\w\\-]+\\.)+[\\w\\-]+")) {
   return false;
  }
  IsEMailResult result = IsEMail.is_email_verbose(email, true);
  switch (result.getState()) {
  case OK:
   return true;
  default:
   return false;
  }
 }