java理解Springboot中的Cron，自动发送电子邮件
关于Cron有很多信息，我有点困惑。大部分信息仅与设置定时cron注释有关。我以前从未使用过SpringBoot调度。我想做的是设置一封电子邮件每月发送一次，比如每个月的15号。在使用EmailService和Helpers之前，我已经发送过电子邮件。将这两种方法结合起来是正确的，还是应该设置电子邮件模板并以不同的方式发送电子邮件？我没有发送电子邮件（当我改为今天的日期和时间时）。有谁能告诉我为什么它没有在预定的时间发送，我是否遗漏了一些代码，或者这不是安排时间的方式吗？我以前使用过这种通过电子邮件服务发送电子邮件的方法，而且它是有效的，所以我设置调度程序的方式肯定有问题。有人知道为什么它没有在预定的时间运行sendReminder（）吗
这是我目前代码中的内容。。。 控制器：
@Controller
public class MailController {
@Autowired
LicenseRepository licenseRepository;
@Autowired
InsuranceRepository insuranceRepository;
@Autowired
EmailService emailService;
@Scheduled(cron = "0 15 10 15 * ?")
public void sendReminder(){
License license = new License();
Insurance insurance = new Insurance();
Mail mail = new Mail();
mail.setFrom("no-reply@gmail.com");
mail.setTo(new String[]{"myemail@gmail.com"});
mail.setSubject("Policy Renewal Notice");
Map<String, Object> mailModel = new HashMap<String, Object>();
mail.setModel(mailModel);
try {
emailService.sendSimpleMessage(mail, license, insurance);
} catch (Exception e) {
e.printStackTrace();
}
}
@RequestMapping(value="/email")
public String email(){
return "emailMessage";
}
}
以及电子邮件服务：
@Service
public class EmailService{
private JavaMailSender javaMailSender;
@Autowired
public EmailService(JavaMailSender javaMailSender){
this.javaMailSender = javaMailSender;
}
@Autowired
private SpringTemplateEngine templateEngine;
public void sendSimpleMessage(Mail mail, License license, Insurance insurance) throws MessagingException, IOException {
MimeMessage message = javaMailSender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message,
MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED,
StandardCharsets.UTF_8.name());
helper.addAttachment("Mail_Icon.png", new ClassPathResource("static/images/Mail_Icon.png"));
Context context = new Context();
context.setVariables(mail.getModel());
context.setVariable("license",license);
context.setVariable("insurance",insurance);
String html = templateEngine.process("emailMessage", context);
helper.setTo(mail.getTo());
helper.setText(html, true);
helper.setSubject(mail.getSubject());
helper.setFrom(mail.getFrom());
javaMailSender.send(message);
}
}
最后是html电子邮件模板：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns:th="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>HTML Reminder Email</title>
<style type="text/css">
lots of styling here removed for easier reading
</style>
</head>
<body bgcolor="#f6f8f1">
<table width="100%" bgcolor="#f6f8f1" border="0" cellpadding="0" cellspacing="0">
<tr>
<td>
<!--[if (gte mso 9)|(IE)]>
<table width="600" align="center" cellpadding="0" cellspacing="0" border="0">
<tr>
<td>
<![endif]-->
<table bgcolor="#ffffff" class="content" align="center" cellpadding="0" cellspacing="0" border="0">
<tr>
<td bgcolor="#6435c9" class="header">
<table width="70" align="left" border="0" cellpadding="0" cellspacing="0">
<tr>
<td height="70" style="padding: 0 20px 20px 0;">
<img class="fix" src="cid:Mail_Icon.png" width="70" height="70" border="0" alt="" />
</td>
</tr>
</table>
<!--[if (gte mso 9)|(IE)]>
<table width="425" align="left" cellpadding="0" cellspacing="0" border="0">
<tr>
<td>
<![endif]-->
<table class="col425" align="left" border="0" cellpadding="0" cellspacing="0" style="width: 100%; max-width: 425px;">
<tr>
<td height="70">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td class="subhead" style="padding: 0">
Policy Renewal Expiration Reminder
</td>
</tr>
</table>
</td>
</tr>
</table>
<!--[if (gte mso 9)|(IE)]>
</td>
</tr>
</table>
<![endif]-->
</td>
</tr>
<tr>
<td class="innerpadding borderbottom">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr class="emailRow">
<p>AFFILIATE NAME HERE</p>
</tr>
<tr class="emailRow">
<p>Our Records indicate that your policy is up for renewal in 30 days. Please provide the updated proof of insurance to the Director of Operations by email: <a href="mailto:myemail@gmail.com">myemail@gmail.com</a>. We appreciate your compliance. </p>
<p>Thank you,</p>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>
这就是我在main中放置Enable Scheduling注释的地方。java文件
@EntityScan(
basePackageClasses = {ODbApplication.class, Jsr310JpaConverters.class}
)
@EnableScheduling
@SpringBootApplication
@Configuration
public class ODbApplication extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(ODbApplication.class);
}
public static void main(String[] args) {
SpringApplication.run(ODbApplication.class, args);
}
@Bean
public FilterRegistrationBean securityDatabaseFilterRegistration(SecurityDatabaseFilter securityDatabaseFilter) {
FilterRegistrationBean registrationBean = new FilterRegistrationBean(securityDatabaseFilter);
registrationBean.setEnabled(false);
return registrationBean;
}
}
# 1 楼答案
理解cron表达式，它由六个字段组成
<year> field is optional.docs*表示all?表示any你知道cron表达式很好，它将在每个月15日的
10:15 AM开始这样做没有坏处，如果这样做不起作用，那么你就错过了一些东西
@EnableScheduling它只会启用该功能
@Scheduled