Thymeleaf Rich HTML 电子邮件错误

Question

首先，我已经阅读了有关 thymeleaf 电子邮件渲染的所有问题，我的意思是，原始教程：

http://www.thymeleaf.org/doc/articles/springmail.html

还有其他有关此问题的 stackoverflow 已解决问题，问题是我无法找到合适的解决方案，而且开始很烦人......所以，请你帮我解决这个问题吗？

问题，这么多人，我想发送丰富的 HTML 邮件，这里是我的 Thymeleaf 配置：

@Configuration
public class ThymeleafConfig {

    @Bean
    public ClassLoaderTemplateResolver emailTemplateResolver(){
        ClassLoaderTemplateResolver emailResolver = new ClassLoaderTemplateResolver();
        emailResolver.setPrefix("/WEB-INF/mailTemplates/");
        emailResolver.setSuffix(".html");
        emailResolver.setTemplateMode("HTML5");
        emailResolver.setOrder(1);
        return emailResolver;
    }

    @Bean
    public ServletContextTemplateResolver webTemplateResolver() {
        ServletContextTemplateResolver webResolver = new ServletContextTemplateResolver();
        webResolver.setPrefix("/WEB-INF/templates/");
        webResolver.setSuffix(".html");
        webResolver.setTemplateMode("HTML5");
        webResolver.setOrder(2);
        return webResolver;
    }

    @Bean
    public SpringTemplateEngine templateEngine() {
        SpringTemplateEngine engine = new SpringTemplateEngine();
        engine.addTemplateResolver(emailTemplateResolver());
        engine.addTemplateResolver(webTemplateResolver());
        engine.addDialect(new SpringSecurityDialect());
        return engine;
    }

    @Bean
    public ThymeleafViewResolver thymeleafViewResolver() {
        ThymeleafViewResolver resolver = new ThymeleafViewResolver();
        resolver.setTemplateEngine(templateEngine());
        resolver.setOrder(1);
        return resolver;
    }
}

在 emailResolver.setPrefix("/WEB-INF/mailTemplates/");我尝试将原始示例配置改为行，例如 emailResolver.setPrefix("/mail/"); 并重新组织 eclipse 项目中的文件。现在是这样的

发送邮件的方法如下：

public void sendRegistrationEmail(String contextPath, Locale locale, User user) throws MessagingException{
        String token = UUID.randomUUID().toString();
        userService.createVerificationToken(user, token);

        String recipientAddress = user.getEmail();
        String subject = "Register";
        String confirmationUrl = contextPath + "/regitrationConfirm.html?token=" + token;

        String imageResourceName= "/images/myLogo.jpg";
        final Context ctx = new Context(locale);
        ctx.setVariable("name", user.getShownUsername());
        ctx.setVariable("subscriptionDate", new Date());
        ctx.setVariable("logo", imageResourceName);
        ctx.setVariable("name", user.getShownUsername());
        ctx.setVariable("loginName", user.getUsername());
        ctx.setVariable("email", user.getEmail());
        ctx.setVariable("link", confirmationUrl);

        final String htmlContent = templateEngine.process("registrationTemplate", ctx);

        final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
        final MimeMessageHelper message = new MimeMessageHelper(mimeMessage);
        message.setFrom("<" + env.getProperty("email.username") + ">");
        message.setTo("<" + recipientAddress + ">");
        message.setSubject(subject);
        message.setText(htmlContent,true);

        mailSender.send(mimeMessage);
    }

当然，还有 Tomcat 表示 Servlet 上下文无法呈现此模板的错误。

我已经调试了 thymelead 代码，当它必须渲染模板时，我检查了它如何尝试使用 ClassLoaderTemplateResolver 渲染邮件：

它只是在日志中写下这条消息：

logger.trace("[THYMELEAF][{}] Template \"{}\" could not be resolved as resource \"{}\" with resource resolver \"{}\"", new Object[] {TemplateEngine.threadIndex(), templateName, resourceName, resourceResolver.getName()});

使用此参数：

resourceName = /WEB-INF/mailTemplates/registrationTemplate.html
templateName = registrationTemplate
resourceResolver.getName() = org.thymeleaf.resourceresolver.ClassLoaderResourceResolver

我很确定错误是某些配置中的小问题或类似的东西，购买我现在不知道在哪里搜索它...

当它不使用 ClassLoader 渲染模板时，异常运行，然后它尝试使用第二个租用模板，即 Servlet 模板，并因这个众所周知的错误而崩溃：

Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateProcessingException: Resource resolution by ServletContext with org.thymeleaf.resourceresolver.ServletContextResourceResolver can only be performed when context implements org.thymeleaf.context.IWebContext [current context: org.thymeleaf.context.Context]] con causa raíz
org.thymeleaf.exceptions.TemplateProcessingException: Resource resolution by ServletContext with org.thymeleaf.resourceresolver.ServletContextResourceResolver can only be performed when context implements org.thymeleaf.context.IWebContext [current context: org.thymeleaf.context.Context]

有什么想法吗？

我已经阅读了这种方法： Using multiple template resolvers with Spring 3.2 and Thymeleaf 2.1.3 for emails

但最好让它与 Thymeleaf 示例这样的配置一起工作，避免发送请求等

提前致谢！

编辑：

要添加更多信息，这里是电子邮件模板：

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
  <head>
    <title th:remove="all">Registration Template</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
  </head>
  <body>
    <p th:text="#{email.registration.greeting(${name})}">
      Hello, Username!
    </p>
    <p>
      Registering on <span th:text="${#dates.format(subscriptionDate)}">Date</span>.
    </p>
    <p>Your data:</p>
    <ul th:remove="all-but-first">
      <li th:text="#{email.registration.loginname(${loginName})}">Login: username</li>
      <li th:text="#{email.registration.shownusername(${shownUserName})}">show name: UserName</li>
      <li th:text="#{email.registration.email(${email})}">email: user@mail.com</li>
    </ul>
    <p>
      Register link:
    </p>
    <p th:text="${link}"></p>
    <p>
      Thanks!
    </p>
    <p>
      <img src="sample.png" th:src="'cid:' + ${logo}" />
    </p>
  </body>
</html>

Answer 1

我几乎可以肯定问题来自此配置：

ClassLoaderTemplateResolver emailResolver = new ClassLoaderTemplateResolver();
emailResolver.setPrefix("/WEB-INF/mailTemplates/");

/WEB-INF/mailTemplates 在战争中不在类路径中。相反，将您的 mailTemplates 文件夹放在 src/resources 中。然后它会被放在 /WEB-INF/classes/ 中，你应该可以通过这个配置访问它们：

ClassLoaderTemplateResolver emailResolver = new ClassLoaderTemplateResolver();
emailResolver.setPrefix("/mailTemplates/");

编辑： 另一种解决方案是对电子邮件模板也使用 ServletContextTemplateResolver ：

ServletContextTemplateResolver emailResolver = new ServletContextTemplateResolver();
emailResolver.setPrefix("/WEB-INF/mailTemplates/");