如何使用ActiveMQ中间件方式发送邮件

使用ActiveMQ中间件方式发送邮件可以极大地提高邮件发送的效率和可靠性，下面是详细的步骤：

前置条件

1. 安装ActiveMQ中间件。
2. 了解Java编程语言，并且熟悉使用Java相关工具和框架。

步骤

1. 引入ActiveMQ相关的依赖：

<dependency>
    <groupId>org.apache.activemq</groupId>
    <artifactId>activemq-all</artifactId>
    <version>${activemq.version}</version>
</dependency>

1. 配置ActiveMQ连接信息：

public class ActiveMQConfig {
    @Value("${spring.activemq.broker-url}")
    private String brokerUrl;

    @Bean
    public ConnectionFactory connectionFactory() {
        ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
        connectionFactory.setBrokerURL(brokerUrl);
        return connectionFactory;
    }
}

1. 编写邮件生产者：

@Service
public class MailProducer {
    @Autowired
    private JmsTemplate jmsTemplate;

    public void sendMail(String to, String subject, String content) {
        jmsTemplate.convertAndSend("mail-queue", new Mail(to, subject, content));
    }
}

1. 编写邮件消费者：

@Service
public class MailConsumer implements MessageListener {
    @Autowired
    private JavaMailSender mailSender;

    @Override
    public void onMessage(Message message) {
        try {
            ObjectMessage objectMessage = (ObjectMessage) message;
            Mail mail = (Mail) objectMessage.getObject();
            SimpleMailMessage mailMessage = new SimpleMailMessage();
            mailMessage.setFrom("[e-mail]");
            mailMessage.setTo(mail.getTo());
            mailMessage.setSubject(mail.getSubject());
            mailMessage.setText(mail.getContent());
            mailSender.send(mailMessage);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

1. 配置邮件发送信息：

@Configuration
public class MailConfig {
    @Value("${spring.mail.host}")
    private String host;

    @Value("${spring.mail.username}")
    private String username;

    @Value("${spring.mail.password}")
    private String password;

    @Value("${spring.mail.properties.mail.smtp.auth}")
    private String auth;

    @Value("${spring.mail.properties.mail.smtp.starttls.enable}")
    private String starttls;

    @Value("${spring.mail.properties.mail.smtp.starttls.required}")
    private String starttlsRequired;

    @Value("${spring.mail.props.mail.smtp.connectiontimeout}")
    private String connectiontimeout;

    @Value("${spring.mail.props.mail.smtp.timeout}")
    private String timeout;

    @Value("${spring.mail.props.mail.smtp.writetimeout}")
    private String writetimeout;

    @Bean
    public JavaMailSender javaMailSender() {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost(host);
        mailSender.setUsername(username);
        mailSender.setPassword(password);

        Properties properties = new Properties();
        properties.put("mail.smtp.auth", auth);
        properties.put("mail.smtp.starttls.enable", starttls);
        properties.put("mail.smtp.starttls.required", starttlsRequired);
        properties.put("mail.smtp.connectiontimeout", connectiontimeout);
        properties.put("mail.smtp.timeout", timeout);
        properties.put("mail.smtp.writetimeout", writetimeout);

        mailSender.setJavaMailProperties(properties);
        return mailSender;
    }
}

1. 编写测试用例：

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailTest {
    @Autowired
    private MailProducer mailProducer;

    @Test
    public void testSendMail() {
        mailProducer.sendMail("[e-mail]", "测试邮件", "这是一封测试邮件");
    }
}

以上就是使用ActiveMQ中间件方式发送邮件的完整攻略。

下面是两条示例：

示例1

首先，我们需要定义一个邮件类：

public class Mail implements Serializable {
    private String to;
    private String subject;
    private String content;

    public Mail(String to, String subject, String content) {
        this.to = to;
        this.subject = subject;
        this.content = content;
    }

    // getter、setter方法省略
}

然后，编写邮件生产者：

@Service
public class MailProducer {
    @Autowired
    private JmsTemplate jmsTemplate;

    public void sendMail(String to, String subject, String content) {
        jmsTemplate.convertAndSend("mail-queue", new Mail(to, subject, content));
    }
}

最后，在测试类中调用邮件生产者的发送方法：

@RunWith(SpringRunner.class)
@SpringBootTest
public class MailTest {
    @Autowired
    private MailProducer mailProducer;

    @Test
    public void testSendMail() {
        mailProducer.sendMail("[e-mail]", "测试邮件", "这是一封测试邮件");
    }
}

示例2

和上面的示例类似，我们需要先定义一个邮件类：

public class Mail implements Serializable {
    private String to;
    private String subject;
    private String content;

    public Mail(String to, String subject, String content) {
        this.to = to;
        this.subject = subject;
        this.content = content;
    }

    // getter、setter方法省略
}

然后，编写邮件消费者：

@Service
public class MailConsumer implements MessageListener {
    @Autowired
    private JavaMailSender mailSender;

    @Override
    public void onMessage(Message message) {
        try {
            ObjectMessage objectMessage = (ObjectMessage) message;
            Mail mail = (Mail) objectMessage.getObject();
            SimpleMailMessage mailMessage = new SimpleMailMessage();
            mailMessage.setFrom("[e-mail]");
            mailMessage.setTo(mail.getTo());
            mailMessage.setSubject(mail.getSubject());
            mailMessage.setText(mail.getContent());
            mailSender.send(mailMessage);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

最后，在Spring Boot应用启动的时候，初始化邮件消费者：

@SpringBootApplication
public class Application {
    @Autowired
    private MailConsumer mailConsumer;

    @Bean
    public DefaultMessageListenerContainer defaultMessageListenerContainer(ConnectionFactory connectionFactory) {
        DefaultMessageListenerContainer container = new DefaultMessageListenerContainer();
        container.setConnectionFactory(connectionFactory);
        container.setDestinationName("mail-queue");
        container.setMessageListener(mailConsumer);
        return container;
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

这样，当有邮件需要发送的时候，邮件生产者会将邮件信息发送到"mail-queue"队列中，邮件消费者则会从队列中取出邮件信息并发送邮件。