Autowire JavaMailSenderImpl error if spring.mail.host is not in application.properties

Question

I have a little "problem" using JavaMailSenderImpl to send letters in my spring boot application.

I try to set all properties dynamically (I want them to be read from the database in the future), but for unknown reasons, the JavaMailSenderImpl auto-messaging only works if "spring.mail.host" is present in my .properties applications.

It doesn’t matter what value I set (it may be empty, it doesn’t matter because I set the correct one later), but the property should be there, or auto-connection will fail.

This is my controller:

import java.util.Properties; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.mail.MailException; import org.springframework.mail.SimpleMailMessage; import org.springframework.mail.javamail.JavaMailSenderImpl; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class MailController { @Autowired private JavaMailSenderImpl ms; @RequestMapping("/mail") public String send(Model model){ SimpleMailMessage message; String fromEmail=" [e-mail] "; String toEmail ="xxxxxxx"; Properties mailProperties = new Properties(); mailProperties.put("mail.smtp.starttls.enable", true); mailProperties.put("mail.smtp.ssl.trust", "smtp.gmail.com"); ms.setHost("smtp.gmail.com"); ms.setPort(587); ms.setUsername("xxxx"); ms.setPassword("yyyyy"); ms.setJavaMailProperties(mailProperties); message = new SimpleMailMessage(); message.setSubject("Test email"); message.setFrom(fromEmail); message.setTo(toEmail); message.setText("Something something"); try{ ms.send(message); } catch(MailException ex){ System.err.println(ex.getMessage()); } return "OK"; } } 

Will work fine (sends an email) using this application.properties:

 #springboot-starter-mail properties spring.mail.host= 

But throw this exception if I remove this line:

 Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.mail.javamail.JavaMailSenderImpl] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] ... 19 common frames omitted 

I could leave the empty property there, but that doesn't seem right.

What ideas might be the reason?

Answer 1

Master JavaMailSender interface instead of implementation.

 @Autowired private JavaMailSender mailSender; 

Answer 2

Do not auto-increment JavaMailSenderImpl . Instead, create a method that creates an instance of JavaMailSenderImpl and returns it with all the necessary parameters. And then call your sender where you need it. If you are autowire mailsender, it enters an instance that already needs the spring.mail.host parameter.