Regular expression for Belgian phone numbers

Nepherte — Thu, 19 Mar 2009 22:02:15 +0000

I needed a regular expression to parse Belgian phone numbers for a program I am writing. At first sight regular expressions can be quite difficult for people to understand. Luckily I have a course at University that studies the mathematics behind regular expressions and the languages they define. A lovely exercise.

Belgian phone numbers comply with following specifications:

The 2 possible formats are 01 234 56 78 and 012 34 56 78.
The first 2 or 3 digits, the zone number, always start with a zero.
The entire phone numer counts 9 digits.

There exist multiple other notations such as 012/34.56.78 and 012/34.56.78. The strenght of a regular expression is that it can describe all these notations in one line. This easy regular expression will do the necessary, though will also accept 10 digit numbers:

[0](?:\\d{1,2})[/. ]?(?:\\d{2,3})[. ]?(?:\\d{2})[. ]?(?:\\d{2})

You could however use a logical ‘or’ between two expressions to make sure only 9 digit phone numbers are accepted:

[0](?:\\d{1})[/. ]?(?:\\d{3})[. ]?(?:\\d{2})[. ]?(?:\\d{2})|[0](?:\\d{2})[/. ]?(?:\\d{2})[. ]?(?:\\d{2})[. ]?(?:\\d{2})

Belgian cell phone numbers on the other hand have a slightly different format so another expression is necessary:

The used format is 0412 34 56 67
The first 2 digits should always start with 04
The total number of digits should always be 10

Again multiple notations exist to write down cell phone numbers. An expression that only accepts this format with the most commonly used notations is:

[0][4](?:\\d{2})[/. ]?(?:\\d{2,3})[. ]?(?:\\d{2})[. ]?(?:\\d{2})

A small program in java that uses these regular expressions could look like:

import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class PhoneNumberValidator {
// Check for valid Belgian phone numbers
public static boolean isValidPhoneNumber(String input) {
Pattern p = Pattern.compile("[0](?:\\d{1,2})[/. ]?(?:\\d{2,3})[. ]?(?:\\d{2})[. ]?(?:\\d{2})");
Matcher m = p.matcher(input);
return m.matches();
}
// Check for valid Belgian cell phone numbers
public static boolean isValidCellPhoneNumber(String input) {
Pattern p = Pattern.compile("[0][4](?:\\d{2})[/. ]?(?:\\d{2,3})[. ]?(?:\\d{2})[. ]?(?:\\d{2})");
Matcher m = p.matcher(input);
return m.matches();
}
}

Howto: Send Mail Over SMTPS In Java

Nepherte — Wed, 19 Dec 2007 16:00:28 +0000

Introduction
This tutorial will show you how to send mail in Java over SMTPS. SMTP, or Simple Mail Transfer Protocol, is the de facto standard for email transmissions across the internet. The SSL protocol, or Secure Socket Layer, provides an encrypted, secure connection. Many providers try to use this secure version of smtp and I encourage everyone to make use of it.

Example code
In the example given, we will use the smtps server of Google. To use this server, you will need a Gmail account. The example makes use of the fictive email account ‘mail@gmail.com’ with ‘password’ and the JavaMail library.

import java.util.Properties;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import com.sun.mail.smtp.SMTPSSLTransport;
 
public static void sendMail(String to, String from, String subject, Multipart content) {
try {
// create properties
Properties props = System.getProperties();
// < -- authorization, i.e. account & password is required -->
props.put("mail.smtps.auth", "true");
// < -- it is important you use the correct port. smtp uses 25, smtps 465 -->
props.put("mail.smtps.port", "465");
// < -- put the smtps server host address here -->
props.put("mail.smtps.host", "smtp.gmail.com");
 
// create session
Session session = Session.getDefaultInstance(props);
session.setDebug(true);
 
// create content
MimeMultipart msgContent = new MimeMultipart("alternative");
 
// Text Mail
MimeBodyPart html = new MimeBodyPart();
// < -- we will send plain text, "text/html" is possible as well -->
html.setContent(content, "text/plain");
html.setHeader("MIME-Version", "1.0");
html.setHeader("Content-Type", "text/plain; charset=iso-8859-1");
msgContent.addBodyPart(html);
MimeMessage msg = new MimeMessage(session);
msg.setContent(content);
// set sender and recipient
msg.setFrom(new InternetAddress(from));
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
msg.setSubject(subject);
 
// transport the message
// < -- we will send the message over smtps -->
SMTPSSLTransport transport = (SMTPSSLTransport)session.getTransport("smtps");
 
// connect to server
// < -- fill in gmail email address and password -->
transport.connect("smtp.gmail.com", "mail@gmail.com", "password");
 
// send the message
transport.sendMessage(msg, msg.getAllRecipients());
// close the connection
transport.close();
} catch> (Exception e) {
e.getStackTrace();
return;
}
}

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Regular expression for Belgian phone numbers

Howto: Send Mail Over SMTPS In Java