Module jakarta.mail
Package jakarta.mail.internet

Class MimeMultipart

java.lang.Object
jakarta.mail.Multipart
jakarta.mail.internet.MimeMultipart
public class MimeMultipart extends Multipart
The MimeMultipart class is an implementation of the abstract Multipart class that uses MIME conventions for the multipart data.

A MimeMultipart is obtained from a MimePart whose primary type is "multipart" (by invoking the part's getContent() method) or it can be created by a client as part of creating a new MimeMessage.

The default multipart subtype is "mixed". The other multipart subtypes, such as "alternative", "related", and so on, can be implemented as subclasses of MimeMultipart with additional methods to implement the additional semantics of that type of multipart content. The intent is that service providers, mail JavaBean writers and mail clients will write many such subclasses and their Command Beans, and will install them into the JavaBeans Activation Framework, so that any Jakarta Mail implementation and its clients can transparently find and use these classes. Thus, a MIME multipart handler is treated just like any other type handler, thereby decoupling the process of providing multipart handlers from the Jakarta Mail API. Lacking these additional MimeMultipart subclasses, all subtypes of MIME multipart data appear as MimeMultipart objects.

An application can directly construct a MIME multipart object of any subtype by using the MimeMultipart(String subtype) constructor. For example, to create a "multipart/alternative" object, use new MimeMultipart("alternative").

The mail.mime.multipart.ignoremissingendboundary property may be set to false to cause a MessagingException to be thrown if the multipart data does not end with the required end boundary line. If this property is set to true or not set, missing end boundaries are not considered an error and the final body part ends at the end of the data.

The mail.mime.multipart.ignoremissingboundaryparameter System property may be set to false to cause a MessagingException to be thrown if the Content-Type of the MimeMultipart does not include a boundary parameter. If this property is set to true or not set, the multipart parsing code will look for a line that looks like a bounary line and use that as the boundary separating the parts.

The mail.mime.multipart.ignoreexistingboundaryparameter System property may be set to true to cause any boundary to be ignored and instead search for a boundary line in the message as with mail.mime.multipart.ignoremissingboundaryparameter.

Normally, when writing out a MimeMultipart that contains no body parts, or when trying to parse a multipart message with no body parts, a MessagingException is thrown. The MIME spec does not allow multipart content with no body parts. The mail.mime.multipart.allowempty System property may be set to true to override this behavior. When writing out such a MimeMultipart, a single empty part will be included. When reading such a multipart, a MimeMultipart will be created with no body parts.