電子郵件丟失圖像附件

Question

我想發送一封電子郵件與來自Java的圖像附件。我正在使用以下代碼段：

String to = "jverstry@gmail.com"; 
String from = "ffff@ooop.com"; 

// Which server is sending the email? 
String host = "localhost"; 

// Setting sending mail server 
Properties properties = System.getProperties(); 
properties.setProperty("mail.smtp.host", host); 

// Providing email and password access to mail server 
properties.setProperty("mail.user", "xxx"); 
properties.setProperty("mail.password", "yyy"); 

// Retrieving the mail session 
Session session = Session.getDefaultInstance(properties); 

// Create a default MimeMessage 
MimeMessage message = new MimeMessage(session); 

message.setFrom(new InternetAddress(from)); 
message.addRecipient(
    Message.RecipientType.TO, new InternetAddress(to)); 

message.setSubject("This an email test !!!"); 

// Create a multipart message 
Multipart mp = new MimeMultipart(); 

// Body text 
BodyPart messageBP = new MimeBodyPart(); 
messageBP.setText("Some message body !!!"); 
mp.addBodyPart(messageBP); 

// Attachment 
BodyPart messageBP2 = new MimeBodyPart(); 

String image = "/MyImage.jpg"; 
InputStream stream = EmailWithAttachment.class 
    .getResourceAsStream(image); 
DataSource source = new ByteArrayDataSource(stream, "image/*"); 

messageBP2.setDataHandler(new DataHandler(source)); 
messageBP2.setHeader("Content-ID", "My Image"); 
mp.addBodyPart(messageBP2); 

message.setContent(mp); 

// Sending the message 
Transport.send(message); 

電子郵件到達我的郵箱，但是當我打開它時，附件不可用。什麼可能導致這個問題？我檢查了.jar，它包含圖像。

Answer 1

好吧，我知道了。我不應該傳遞輸入流，而是傳遞一個字節數組，並設置更精確的MIME類型。我修改了我的代碼，如下所示，它的工作原理如下：

DataSource source = new ByteArrayDataSource(
    IOUtils.toByteArray(is), "image/jpeg"); 

Answer 2

 // Part two is attachment 
    messageBodyPart = new MimeBodyPart(); 
    String filename = "file.txt"; 
    DataSource source = new FileDataSource(filename); 
    messageBodyPart.setDataHandler(new DataHandler(source)); 
    messageBodyPart.setFileName(filename); 
    multipart.addBodyPart(messageBodyPart); 

來源：http://www.tutorialspoint.com/java/java_sending_email.htm