spring mvc send email (javamail) exception not getting caught

Question

I am trying to send an email but before I was getting a nullpointerexception error which was due to mailSender not getting set correctly, now I edited the code as it is shown below and I am not getting any exception but the code breaks at the line

MimeMessage message = mailSender.createMimeMessage();

Here is my code (both sendMail() and addNewAlarm() are inside the same class "ElementService"):

public class ElementService implements ApplicationContextAware {
    private ApplicationContext ac;



public void sendMail(String toAddress, String subject, String body) throws  Exception{

   JavaMailSender mailSender = (JavaMailSender) ac.getBean("mailSender");
   MimeMessage message = mailSender.createMimeMessage();

   try{
    MimeMessageHelper helper = new MimeMessageHelper(message, true);

    helper.setFrom("xxx@gmail.com");
    helper.setTo(toAddress);
    helper.setSubject(subject);
    helper.setText(body);


     }catch (MessagingException e) {
        throw new MailParseException(e);
     }
       try{
           mailSender.send(message);
       }
       catch(Exception e){
           throw e;
       }

  }    

   //I want an email to be sent every 30 seconds
   @Scheduled(fixedDelay = 30*1000)
   public void function2RepeatEvery30Seconds()
   {
       MailService mailer = (MailService) ac.getBean("mailService");
       mailer.sendMail("xxx@hotmail.com","subject","body");
       //does other stuff..

    }  
    @Override
    public void setApplicationContext(ApplicationContext ac) throws BeansException {
        this.ac = ac;
    }

}

These are the beans in my xml:

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">

<!-- SMTP settings -->
<property name="host" value="smtp.gmail.com" />
<property name="port" value="587" />
<property name="username" value="***@gmail.com" />
<property name="password" value="*****" />

<property name="javaMailProperties">
    <!-- additional properties specific to JavaMail -->
    <props>
        <prop key="mail.transport.protocol">smtp</prop>
        <prop key="mail.smtp.auth">true</prop>
        <prop key="mail.smtp.starttls.enable">true</prop>
    </props>
</property>
</bean>

In debug mode I can see that mailSender has been set according to the properties shown on the mailSender bean.

Answer 1

I finally did it!! Thanks to Serge Ballesta of course. I should have been using log4j all along... I researched the Exception MessageRemovedIOException and I found this post java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger for JUnit test case for Java mail where there is a suggestion in the comments to change

<dependency> <groupId>javax.mail</groupId> <artifactId>javax.mail-api</artifactId> <version>1.5.2</version> </dependency>

to

<dependency> <groupId>com.sun.mail</groupId> <artifactId>javax.mail</artifactId> <version>1.5.2</version> </dependency>

I also had to change this:

<prop key="mail.smtp.starttls.enable">true</prop>

to this:

<prop key="mail.smtp.starttls.enable">false</prop>

Thank you very much for your time and advice @Serge Ballesta!

Answer 2

Ok, obviously the mailSender is null which causes the error. My guess would be that your @Autowired annotation is not processed. Do you have AutowiredAnnotationBeanPostProcessor registered? You can do that for example by using <context:annotation-config /> in your Spring configuration.

Other option (without using @Autowired) is to manually specify the dependency on mailSender in your mailService bean definition like so:

<bean id="mailService" class="gr.mobics.allweb.service.MailService" scope="singleton">
    <property name="mailSender" ref="mailSender" />
</bean>

I have not tested this, but it seems like this is the cause of your problem. If these solutions don't work you, leave a comment and I'll try to update the answer.