Java: Sending mails with Spring

Java: Sending mails with Spring

In this blog we will take a look at creating a mailer util with Spring and the Spring MailSender class. First of all lets take a look at the part which has to be inserted into the application context xml file.

Configuring the Spring mail bean in the application-context

<!-- Spring Mail Sender config -->
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="host" value="smtp-server.com" />
    <property name="port" value="587" />
    <property name="username" value="username" />
    <property name="password" value="password" />

    <property name="javaMailProperties">
       <props>
       	      <prop key="mail.smtp.auth">true</prop>
       	      <prop key="mail.smtp.starttls.enable">true</prop>
       	   </props>
    </property>
</bean>

<!-- Here we initialize a utility which will use our bean.
    This way it is possible to autowire/inject the mailer everywhere
    it is needed.
-->
<bean id="mailUtility" class="me.kamwo.mail.utility.MailUtility" />

In this part we have done two different things. First we are telling the application that there is a Bean called mailSender and that it is of the type org.springframework.mail.javamail.JavaMailSenderImpl. This class contains a implementation for the Java Mail API. The following part configures the “mail”-bean. It tells the application where to connect to and how to authenticate with the smtp-servers of the email provider.

The last part above is the definition of a new bean, called the mailUtility.

<bean id="mailUtility" class="me.kamwo.mail.utility.MailUtility" />

It initializes the MailUtility class, which uses the mailSender-Bean (first bean) and is nothing more than a wrapper around it. Declaring it as a Bean makes sending a mail very easy: You just need to autowire/inject it into your class and send the mail.

MailUtility: Wrapper around the Spring MailSender

Below you will find a quite simple wrapper around the MailSender class for sending plain text messages. It just depends on your use-cases ;-)

/*
 * MailUtility.java
 *
 */
package me.kamwo.mail.utility;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.mail.MailSender;
import org.springframework.mail.SimpleMailMessage;

/**
 *
 * @author kwozniak
 */
public class MailUtility {

    @Autowired
    private MailSender mailSender;

    private String fromAddress = "admin@example.com";

    private String toAddress = "someoneElse@example.com";

    private String subject = "Default mailer subject";

    private String message = "Hi, your order is ready :-)";

    /**
     * Sends an email.
     *
     * @param from Senders email address
     * @param to Receivers email address
     * @param subject Subject of the email
     * @param msg msg of the email.
     */
    public void sendMail(String from, String to, String subject, String msg) {

        SimpleMailMessage mailMessage = new SimpleMailMessage();

        mailMessage.setFrom(from);
        mailMessage.setTo(to);
        mailMessage.setSubject(subject);
        mailMessage.setText(msg);
        mailSender.send(mailMessage);
    }

    /**
     * Sends an email. The senders address will be the default one.
     *
     * @param to Receivers email address
     * @param subject Subject of the email
     * @param msg msg of the email.
     */
    public void sendMail(String to, String subject, String msg) {
        sendMail(fromAddress, to, subject, msg);
    }

    /**
     * Sends an email. The senders and recipient address will be the default ones.
     *
     * @param subject Subject of the email
     * @param msg msg of the email.
     */
    public void sendMail(String subject, String msg) {
        sendMail(fromAddress, toAddress, subject, msg);
    }

    /**
     * Sends an email. The senders and recipient address and also the default subject,
     * will be the default one.
     *
     * @param msg msg of the email.
     */
    public void sendMail(String msg) {
        sendMail(fromAddress, toAddress, subject, msg);
    }
}

Autowiring the mailUtility

Wherever you would like to use the mail utility, you can just inject it in any class you want. See the code fragment below.

@Inject
private MailUtility mailUtility;