java - 通过javamail在邮件中嵌入图像时出错

Question

这是我使用 javax.mail.1.5.2 向用户发送邮件的代码。我需要附上一些图片。我为此使用了servetcontext getRealPath。但它说 ServletContextEvent 变量 sce (参见代码)需要初始化。有一些东西缺失了。这是我的代码。

public void sendSSLMessage(String recipients[], String subject,
                String htmlText, String from , MailSSLSocketFactory sf) throws MessagingException {
            boolean debug = true;
            Properties props = new Properties();
            props.put("mail.smtp.host", SMTP_HOST_NAME);
            props.put("mail.smtp.auth", "true");
            props.put("mail.debug", "true");
            props.put("mail.smtp.port", SMTP_PORT);
            props.put("mail.smtp.socketFactory.port", SMTP_PORT);
            props.put("mail.smtp.socketFactory.class", SSL_FACTORY);
            props.put("mail.smtp.socketFactory.fallback", "false");

            Session session = Session.getDefaultInstance(props,
                    new javax.mail.Authenticator() 
                     {
                         protected PasswordAuthentication                   

                      getPasswordAuthentication() {
                            return new   
                         PasswordAuthentication("support@jiffie.in", "support@1234$");
                        }
                    });

            session.setDebug(debug);
            MimeMessage message = new MimeMessage(session);
            /*Message msg = new MimeMessage(session);*/
            InternetAddress addressFrom = new InternetAddress(from);
            message.setFrom(addressFrom);

            InternetAddress[] addressTo = new InternetAddress[recipients.length];
            for (int i = 0; i < recipients.length; i++) {
                addressTo[i] = new InternetAddress(recipients[i]);
            }
            message.setRecipients(Message.RecipientType.TO, addressTo);
            MimeMultipart multipart = new MimeMultipart("related");

            // first part  (the html)
            BodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setContent(htmlText, "text/html");

            // add it
            multipart.addBodyPart(messageBodyPart);

            // second part (the image)
            messageBodyPart = new MimeBodyPart();
            ServletContextEvent sce; 
            ServletContext context = sce.getServletContext(); //this shows error. sce may not have been initialized
            String contextPath = context.getRealPath("/");
            //...
            File contextDir = new File(contextPath);
            File emailImage = new File(contextDir, "img/logo.png");
            DataSource fds = new FileDataSource(emailImage );
            messageBodyPart.setDataHandler(new DataHandler(fds));
            messageBodyPart.setHeader("Content-ID","<logo>");
            multipart.addBodyPart(messageBodyPart);

            // put everything together
            message.setContent(multipart);

            // Setting the Subject and Content Type
            message.setSubject(subject);

            Transport.send(message);
       }

Answer 1

首先，通过修复所有这些 common JavaMail mistakes 来清理您的代码.

sce 只是出现在程序的中间，而没有被分配值，这就是它提示未初始化的原因。但实际上，如果您只需要 ServletContext，请摆脱 sce 并使用 javax.servlet.ServletRequest 方法 getServletContext()。但是您需要从调用此方法的 Servlet 中传入“请求”对象。