Email protocols
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SMTP: upload and transfer between mail servers.
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POP3: pull emails to local.
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IMAP: After receiving the email, the email is still reserved on the server. Mapping client and server.
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Mime: SMTP was using ASCII. Mime extends to binary transfer.
Unit test
We need to add two annotations in the unit test class
@RunWith(SpringRunner.class)
@SpringBootTest
Spring-boot-starter-mail
- Maven dependency
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>
- property file
spring.mail.host=smtp.gmail.com
spring.mail.username=<your email username>
spring.mail.password=<your email password>
spring.mail.default-encoding=utf-8
#If you use Gmail, the follow two lines are necessary
spring.mail.properties.mail.smtp.socketFactory.port = 465
spring.mail.properties.mail.smtp.socketFactory.class = javax.net.ssl.SSLSocketFactory
Sending a simple text email
@Service
public class MailService {
@Value("${spring.mail.username}")
private String from;
@Autowired
private JavaMailSender mailSender;
public void sendSimpleMail(String to, String subject, String content) {
SimpleMailMessage message = new SimpleMailMessage();
message.setTo(to);
message.setSubject(subject);
message.setText(content);
message.setFrom(from);
mailSender.send(message);
}
}
Test this service
@RunWith(SpringRunner.class)
@SpringBootTest
public class MailServiceTest {
@Resource
MailService mailService;
@Test
public void sendSimpleMail() {
mailService.sendSimpleMail("<Send to email address>",
"Test email",
"Hello World");
}
}
Sending a HTML email
public void sendHTMLMail(String to, String subject, String content) throws MessagingException {
MimeMessage message = mailSender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setFrom(from);
helper.setTo(to);
helper.setSubject(subject);
helper.setText(content, true);
mailSender.send(message);
}
Test this service
@Test
public void sendHTMLMail() throws MessagingException {
String content = "<html>\n<body>\n<h3> Hello world! This is a HTML email.</h3>\n</body>\n</html>";
mailService.sendHTMLMail("<Send to email address>", "HTML Email", content);
}
Sending an email with attachments
public void sendAttachmentMail(String to, String subject, String content, String filePath) throws MessagingException {
MimeMessage message = mailSender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setFrom(from);
helper.setTo(to);
helper.setSubject(subject);
helper.setText(content, true);
FileSystemResource file = new FileSystemResource(new File(filePath));
String filename = file.getFilename();
helper.addAttachment(filename, file);
mailSender.send(message);
}
@Test
public void sendAttachmentMail() throws MessagingException {
String filePath = "C:\\Users\\***";
mailService.sendAttachmentMail("<Send to email address>",
"Test email",
"Hello World", filePath);
}