如何测试JavaMailSender？

我的问题不大。我创建了 MailService 来发送邮件。当我运行程序时，它有效。我拥有的所有可通过电子邮件发送的属性resources/application.properties。我在用着spring-boot-starter-mail.

@Service
public class MailService {
    private JavaMailSender javaMailSender;

    @Autowired
    public MailService(JavaMailSender javaMailSender) {
        this.javaMailSender = javaMailSender;
    }

    public void sendMail(String subject, String messageContent, String recipient)
            throws MessagingException {
        MimeMessage mimeMessage = javaMailSender.createMimeMessage();
        MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage);
        messageHelper.setTo(recipient);
        messageHelper.setSubject(subject);
        messageHelper.setText(messageContent);
        javaMailSender.send(mimeMessage);
    }
}

但我不知道如何为其创建测试。我尝试过类似的东西，我在哪里使用org.jvnet.mock-javamail:mock-javamail，但它不起作用：

public class MailServiceTest {
    private MailService mailService;

    @Mock
    private JavaMailSender javaMailSender;


    @Before
    public void setUp() {
        MockitoAnnotations.initMocks(this);
        mailService = new MailService(javaMailSender);
        Mailbox.clearAll();
    }

    @Test
    public void sendMailTest() throws MessagingException, IOException {
        String subject = "Some subject";
        String body = "Some contents.";
        String recipient = "[email protected] /cdn-cgi/l/email-protection";

        mailService.sendMail(subject, body, recipient);
        List<Message> inbox = Mailbox.get(recipient);
        assertTrue(inbox.size() == 1);
        assertEquals(subject, inbox.get(0).getSubject());
        assertEquals(body, inbox.get(0).getContent());
    }
}

你可以测试一下如何MimeMessage成立于：

public class EmailServiceTest {

    private EmailServiceImpl emailServiceImpl;

    private JavaMailSender javaMailSender;

    private MimeMessage mimeMessage;

    @Before
    public void before() {
        mimeMessage = new MimeMessage((Session)null);
        javaMailSender = mock(JavaMailSender.class);
        when(javaMailSender.createMimeMessage()).thenReturn(mimeMessage);
        emailServiceImpl = new EmailService(javaMailSender);
    }

    @Test
    public void emailTest() {
        String recipient = "[email protected] /cdn-cgi/l/email-protection"
        EmailRequest request = new EmailRequest();
        request.setRecipient(recipient);
        emailServiceImpl.send(request);
        assertEquals(recipient, mimeMessage.getRecipients(RecipientType.TO)[0].toString());
    }
}