SpringBoot发送异步邮件流程与实现详解

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ MimeMessage.class, MimeType.class, MailSender.class })
@ConditionalOnMissingBean(MailSender.class)
@Conditional(MailSenderCondition.class)	
@EnableConfigurationProperties(MailProperties.class)			//配置文件绑定
@Import({ MailSenderJndiConfiguration.class, MailSenderPropertiesConfiguration.class })
public class MailSenderAutoConfiguration {

	static class MailSenderCondition extends AnyNestedCondition {

		MailSenderCondition() {
			super(ConfigurationPhase.PARSE_CONFIGURATION);
		}
		// 配置文件前缀名称
		@ConditionalOnProperty(prefix = "spring.mail", name = "host")
		static class HostProperty {

		}

		@ConditionalOnProperty(prefix = "spring.mail", name = "jndi-name")
		static class JndiNameProperty {

		}
	}
}

spring:
  mail:
    username: xxxx@163.com
    password: 授权码
    host: smtp.163.com				# 不同邮箱对应的服务器不一样
    default-encoding: UTF-8
    
#    username: xxxx@qq.com
#    password: 授权码
#    host: smtp.qq.com

@Configuration
@EnableAsync//开启异步
public class ThreadPoolConfig {

    @Bean("threadPool")
    public TaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        // 设置核心线程数
        executor.setCorePoolSize(5);
        // 设置最大线程数
        executor.setMaxPoolSize(10);
        // 设置队列容量
        executor.setQueueCapacity(100);
        // 设置线程活跃时间（秒）
        executor.setKeepAliveSeconds(60);
        // 设置默认线程名称
        executor.setThreadNamePrefix("Thread-");
        // 设置拒绝策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 等待所有任务结束后再关闭线程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        return executor;
    }
}

public class EmailUtil {

    private static final String content = "这是邮件的主内容";
	
	// 纯文本邮件
    public static SimpleMailMessage simple(String from, String to){
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject("欢迎xxx");
        message.setText(content);
        return message;
    }

	// 多媒体邮件
    public static MimeMessage mimeMessage(MimeMessage message,String from, String to) throws MessagingException {
        MimeMessageHelper helper = new MimeMessageHelper(message,true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject("复杂邮件主题");
        helper.setText("<p style='color: deepskyblue'>这是浅蓝色的文字</p>", true);
        helper.addAttachment("1.docx", new File("C:\\Users\\Splay\\Desktop\\说明书.docx"));
        helper.addAttachment("1.pdf", new File("C:\\Users\\Splay\\Desktop\\参考.pdf"));
        return message;
    }
}

@Service
public class SendEmailService {

	// SpringBoot自动装配的邮件发送实现类
    @Autowired
    JavaMailSenderImpl mailSender;

    @Async("threadPool")
    public void sendSimpleMail(String from, String to) {
        SimpleMailMessage message = EmailUtil.simple(from, to);
        mailSender.send(message);                   //简单纯文本邮件发送
    }

    @Async("threadPool")
    public void sendMultiPartMail(String from, String to) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessage mimeMessage = EmailUtil.mimeMessage(message,from, to);
        mailSender.send(mimeMessage);               //复杂邮件发送
    }

}

@Controller
public class RouterController {

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


    @Autowired
    SendEmailService mail;

    @RequestMapping("/simple")
    @ResponseBody
    public String simpleMail(@RequestParam(required = true,name = "mail",defaultValue = "xxx@qq.com") String to) {
        mail.sendSimpleMail(from, to);
        return "Send SimpleEmail Successful!";
    }

    @RequestMapping("/complex")
    @ResponseBody
    public String complexMail(@RequestParam(required = true,name = "mail",defaultValue = "xxx@qq.com") String to) throws MessagingException {
        mail.sendMultiPartMail(from, to);
        return "Send SimpleEmail Successful!";
    }
}