Simplest way to send a sendgrid email in spring boot

Question

I am trying to send stacktrace emails in Spring. Here is what I have so far:

# application.properties
spring.sendgrid.api-key="SG.o1o9MNb_QfqpasdfasdfasdfpLX3Q"

And in my ErrorController:

    // Send Mail
    Email from = new Email("david@no-reply.com");
    String subject = "Exception " + message.toString();
    Email to = new Email("tom@gmail.com");
    Content content = new Content("text/plain", trace);
    Mail mail = new Mail(from, subject, to, content);
    Request r = new Request();

    try {
        SendGrid sendgrid = new SendGrid();
        r.setMethod(Method.POST);
        r.setEndpoint("mail/send");
        r.setBody(mail.build());
        Response response = sendgrid.api(request);
        sendgrid.api(r);
    } catch (IOException ex) {

    }

However, it seems like it's not initializing the SendGrid object correctly (with the API key from application.properties). What would be the correct way to do the above?

Answer 1

The SendGrid object should not be created explicitly, but it should be passed as a bean and in this case Spring will initialize it with the API key appropriately (check the code that is responsible for autoconfiguration). So it should look like this:

@Service
class MyMailService {

    private final SendGrid sendGrid;

    @Inject
    public SendGridMailService(SendGrid sendGrid) {
        this.sendGrid = sendGrid;
    }

    void sendMail() {
        Request request = new Request();
        // .... prepare request
        Response response = this.sendGrid.api(request);                
    }
}

Latter you can use this service in your controller by injecting it, for example:

@Controller
public class ErrorController {

     private final emailService;

     public ErrorController(MyMailService emailService) {
           this.emailService = emailService;
     } 

     // Now it is possible to send email 
     // by calling emailService.sendMail in any method
}