使用 Spring Boot 时如何使用 SpringTemplateEngine

Posted 2023-02-26

【中文标题】使用 Spring Boot 时如何使用 SpringTemplateEngine

【英文标题】：How to use SpringTemplateEngine when using Spring Boot

【发布时间】：2015-05-13 16:11:21

【问题描述】：

我正在使用 Thymeleaf SpringTemplateEngine 在我的 Spring 应用程序上创建 html 电子邮件。当我使用纯 Spring MVC 时，一切都很完美。现在使用 Spring Boot，该类找不到我的 .html 模板。我认为问题在于 ServletContext 没有返回正确的路径，但我不知道如何解决它。那么我应该使用另一个上下文来处理模板吗？哪一个？

这是我为纯 Spring MVC 工作的 MailService。

@Service
public class MailService 

    private JavaMailSenderImpl mailSender;

    private SpringTemplateEngine templateEngine;

    public MailService() 
        mailSender = new JavaMailSenderImpl();
        //mailSender config

        templateEngine = new SpringTemplateEngine();
        Set<ITemplateResolver> templatesResolvers = new HashSet<ITemplateResolver>();

        ClassLoaderTemplateResolver emailTemplateResolver = new ClassLoaderTemplateResolver();
        emailTemplateResolver.setPrefix("mail/");
        emailTemplateResolver.setTemplateMode("HTML5");
        emailTemplateResolver.setCharacterEncoding("UTF-8");
        emailTemplateResolver.setOrder(1);
        templatesResolvers.add(emailTemplateResolver);

        ServletContextTemplateResolver webTemplateResolver = new ServletContextTemplateResolver();
        webTemplateResolver.setPrefix("/mail/");
        webTemplateResolver.setTemplateMode("HTML5");
        webTemplateResolver.setCharacterEncoding("UTF-8");
        webTemplateResolver.setOrder(2);
        templatesResolvers.add(webTemplateResolver);

        templateEngine.setTemplateResolvers(templatesResolvers);
    

    public void sendReport(String nome, String email, String obra,
            long medicao, HttpServletRequest request,
            HttpServletResponse response, ServletContext context, Locale locale)
            throws MessagingException 

        String subject = "Novo relatório";

        final WebContext ctx = new WebContext(request, response, context,
                locale);
        ctx.setVariable("nome", nome);
        ctx.setVariable("obra", obra);
        ctx.setVariable("data", DataUtils.getInstance().getDataString(medicao));
        ctx.setVariable("logo", "logo.jpg");

        final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
        final MimeMessageHelper message = new MimeMessageHelper(mimeMessage,
                true, "UTF-8");
        message.setSubject(subject);
        try 
            message.setFrom(new InternetAddress(mailSender.getUsername(),
                    "Sistema"));
         catch (UnsupportedEncodingException e) 
        
        message.setTo(email);

        final String htmlContent = this.templateEngine.process(
                "email-relatorio.html", ctx);
        message.setText(htmlContent, true);

        try 
            File file = new File(context.getRealPath("app/img/logo-pro.jpg"));
            InputStreamSource imageSource = new ByteArrayResource(
                    IOUtils.toByteArray(new FileInputStream(file)));
            message.addInline("logo.jpg", imageSource, "image/jpg");
         catch (IOException e) 
            e.printStackTrace();
        

        this.mailSender.send(mimeMessage);
    

错误：

org.thymeleaf.exceptions.TemplateInputException: Error resolving template "email-relatorio.html", template might not exist or might not be accessible by any of the configured Template Resolvers
    at org.thymeleaf.TemplateRepository.getTemplate(TemplateRepository.java:246)
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1104)
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1060)
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1011)
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:924)
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:898)

【参考方案1】：

您正在使用 Spring Boot，然后让 Spring Boot 完成繁重的工作，它已经完成了。删除您的构造函数，只需 @Autowire JavaMailSender 和 SpringTemplateEngine。

将邮件配置添加到application.properties。

spring.mail.host=your-mail-server
spring.mail.port=
spring.mail.username
spring.mail.password

将百里香叶配置添加到 application.properties

# THYMELEAF (ThymeleafAutoConfiguration)
spring.thymeleaf.check-template-location=true
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.excluded-view-names= # comma-separated list of view names   that should be excluded from resolution
spring.thymeleaf.view-names= # comma-separated list of view names that can be resolved
spring.thymeleaf.suffix=.html
spring.thymeleaf.mode=HTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.content-type=text/html # ;charset=<encoding> is added
spring.thymeleaf.cache=true # set to false for hot refresh

如果你这样做了，请改变你的班级

@Service
public class MailService 

    @Autowired
    private JavaMailSender mailSender;

    @Autowired
    private SpringTemplateEngine templateEngine;

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

    public void enviarRelatorio(String nome, String email, String obra,long medicao, Locale locale) throws MessagingException 

        String subject = "Novo relatório";

        final Context ctx = new Context(locale);
        ctx.setVariable("nome", nome);
        ctx.setVariable("obra", obra);
        ctx.setVariable("data", DataUtils.getInstance().getDataString(medicao));
        ctx.setVariable("logo", "logo.jpg");

        final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
        final MimeMessageHelper message = new MimeMessageHelper(mimeMessage,true, "UTF-8");
        message.setSubject(subject);
        message.setTo(email);

        try 
            message.setFrom(new InternetAddress(username, "Sistema"));
         catch (UnsupportedEncodingException e) 
        

        final String htmlContent = this.templateEngine.process( "email-relatorio", ctx);
        message.setText(htmlContent, true);

        try 
            message.addInline("logo.jpg", new FileSystemResource("imgs/logo-pro.jpg"), "image/jpg");
         catch (IOException e) 
            e.printStackTrace();
        

        this.mailSender.send(mimeMessage);
    

【讨论】：

嗨！我现在正在使用 application.properties。但是，前缀“classpath:/templates/”会引发相同的错误，如果我设置为“templates/”，ThymeleafAutoConfiguration 会引发“找不到模板位置：模板/（请添加一些模板或检查您的 Thymeleaf 配置）”。我的文件在 src/main/resources/templates 中。我错过了什么？

算了。问题是因为我传递了文件的全名，但是有一个后缀。使用 getUsername 时，请将“email-relatorio.html”更改为“email-relatorio”，并将 JavaMailSender 转换为 JavaMailSenderImpl。谢谢！

您不应该强制转换或使用getUsename，只需使用基于@Value 的属性注入属性即可。查看修改后的代码。由于 AOP 可用，转换可能会出现问题，因此您无法转换为 JavaMailSenderImpl，而只能转换为接口。接下来，您应该对接口而不是具体类进行编程....此外，src/main/resources/templates 是默认位置，因此您无需对其进行配置。