Question

我的Java Spring Boot项目中有一个emailService实现。要发送电子邮件，我使用JavaMailSender。在我的服务中，我需要访问HttpServletRequest和HttpServletResponse才能实例化WebContext。现在我通过我的mailsender方法传递这些2 - 请求和响应听起来像个坏主意。我希望将它们放在我的服务中，这样我就可以在我的mailsender中调用只有2个变量的方法：要使用的电子邮件模板和将在该电子邮件上打印的变量映射。有没有办法在我的服务中实例化请求和响应？我可以以某种方式在服务中自动装配它们吗？这就是我的服务的样子：

@Service
@Qualifier("MailSender")
public class MailSenderService {

@Autowired 
private JavaMailSender mailSender;

@Autowired 
private ServletContextTemplateResolver emailTemplateResolver;


public boolean sendMail(HttpServletRequest request, HttpServletResponse     
response, HashMap<String, String> info, String template) throws 
MessagingException, IOException{

    final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
    final MimeMessageHelper message = new 
    MimeMessageHelper(mimeMessage,true, "UTF-8"); // true = multipart

        message.setFrom("sender@example.com");
        message.setTo("mymail@example.com");
        message.setSubject("This is the message subject");
        TemplateEngine engine = new TemplateEngine();
        engine.setTemplateResolver(emailTemplateResolver);
        WebContext ctx =  new WebContext(request, response, 
        request.getServletContext(), request.getLocale());

        ctx.setVariable("info", info);


    try{        
        String messageContent=  engine.process(template, ctx);
        mimeMessage.setContent(tt, "text/html; charset=utf-8");

    }catch(Exception e){
        e.printStackTrace();
    }

    this.mailSender.send(mimeMessage);
    return true;

}
}

Answer 1

如果类是请求作用域，您可以按如下方式自动装配：

@Autowired private HttpServletRequest request;

干杯..

Answer 2

您应该可以自动加载HttpServletRequest，尽管同样不适用于HttpServletResponse。

例如

@Autowired HttpServletRequest request; // works
@Autowired HttpServletResponse response; // doesn't work

有一些关于here的讨论 - 但最后看起来你可能不得不手动传递回复。

Answer 3

对于初学者，您MailSenderService不应该为创建TemplateEngine而烦恼，也不应该知道如何解析模板，这应该是透明的。请参阅Thymeleaf网站上的this turorial。

假设您正在使用XML进行bean配置，而Spring 4则添加以下内容。（您可能已经配置了ServletContextTemplateResolver的实例。）

<bean id="webTemplateResolver" class="org.thymeleaf.templateresolver.ServletContextTemplateResolver">
  <property name="prefix" value="/WEB-INF/templates/" />
  <property name="templateMode" value="HTML5" />
  <property name="characterEncoding" value="UTF-8" />
  <property name="order" value="2" />
</bean>

<!-- THYMELEAF: Template Engine (Spring3-specific version) -->
<bean id="templateEngine" class="org.thymeleaf.spring4.SpringTemplateEngine">
  <property name="templateResolvers">
    <set>
      <ref bean="emailTemplateResolver" />
      <ref bean="webTemplateResolver" />
    </set>
  </property>
</bean>

现在，在您的MailSenderService中，您只需注入TemplateEngine。

@Service
@Qualifier("MailSender")
public class MailSenderService {

@Autowired 
private JavaMailSender mailSender;

@Autowired 
private TemplateEngine engine;

    public boolean sendMail(HttpServletRequest request, HttpServletResponse response, HashMap<String, String> info, String template) throws MessagingException, IOException{

        final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
        final MimeMessageHelper message = new 
        MimeMessageHelper(mimeMessage,true, "UTF-8"); // true = multipart

        message.setFrom("sender@example.com");
        message.setTo("mymail@example.com");
        message.setSubject("This is the message subject");

        WebContext ctx =  new WebContext(request, response, 
        request.getServletContext(), request.getLocale());

        ctx.setVariable("info", info);

        try{        
            String messageContent=  engine.process(template, ctx);
            mimeMessage.setContent(tt, "text/html; charset=utf-8");

        }catch(Exception e){
            e.printStackTrace();
        }

        this.mailSender.send(mimeMessage);
        return true;

    }
}

而不是request.getLocale()只需使用LocaleContextHolder.getLocale()，并将模板中所需的所有属性放在info变量中。有了这个，您可以将方法重写为以下内容。

public boolean sendMail(Map<String, String> info, String template) throws MessagingException, IOException{

        final MimeMessage mimeMessage = this.mailSender.createMimeMessage();
        final MimeMessageHelper message = new 
        MimeMessageHelper(mimeMessage,true, "UTF-8"); // true = multipart

        message.setFrom("sender@example.com");
        message.setTo("mymail@example.com");
        message.setSubject("This is the message subject");

        Context ctx =  new Context(LocaleContextHolder.getLocale());
        ctx.setVariable("info", info);

        try{        
            String messageContent=  engine.process(template, ctx);
            mimeMessage.setContent(tt, "text/html; charset=utf-8");

        }catch(Exception e){
            e.printStackTrace();
        }

        this.mailSender.send(mimeMessage);
        return true;

    }

HttpServletRequest和HttpServletResponse不再需要了。只是一个简单的服务。通常，您不希望您的服务层依赖于Web，因为这是您在解决方案中有效执行的操作。

Answer 4

所以这就是我用注释解决它的方法。非常感谢M. Deinum！

我终于完成了所有工作。我没有使用XML。我使用Spring Boot但是如果我想配置一些东西，那就是我的配置方法。对于像我一样迷失的每个人，这是我在@Configuration类中的templateEngine配置：

 @Bean
public ClassLoaderTemplateResolver emailTemplateResolver(){
    ClassLoaderTemplateResolver emailTemplateResolver = new      
    ClassLoaderTemplateResolver();
        emailTemplateResolver.setPrefix("/WEB-INF/emails/");
        emailTemplateResolver.setSuffix(".html");
        emailTemplateResolver.setTemplateMode("HTML5");
        emailTemplateResolver.setCharacterEncoding("UTF-8");
        emailTemplateResolver.setOrder(1);
        return emailTemplateResolver;
    }

    @Bean
    public TemplateEngine templateEngine(){
        TemplateEngine templateEngine = new TemplateEngine();
        templateEngine.setTemplateResolver(emailTemplateResolver());
        return templateEngine;
    }

通过这种配置我可以@Autowire

   private TemplateEngine templateEngine;

在我的服务中，现在我不需要请求，回复。一切都适用于Context

在Java Spring Service中访问HttpServletRequest和HttpServletResponse

4 个答案: