javax.mail.internet
Class MimeMultipart
public class MimeMultipart
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 JavaMail 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 JavaMail 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").
protected DataSource | ds- The DataSource supplying our InputStream.
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protected boolean | parsed- Have we parsed the data from our InputStream yet?
Defaults to true; set to false when our constructor is given
a DataSource with an InputStream that we need to parse.
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MimeMultipart()- Default constructor.
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MimeMultipart(DataSource ds)- Constructs a MimeMultipart object and its bodyparts from the given
DataSource.
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MimeMultipart(String subtype)- Construct a MimeMultipart object of the given subtype.
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protected InternetHeaders | createInternetHeaders(InputStream is)- Create and return an InternetHeaders object that loads the headers
from the given InputStream.
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protected MimeBodyPart | createMimeBodyPart(InputStream is)- Create and return a MimeBodyPart object to represent a body part parsed
from the InputStream.
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protected MimeBodyPart | createMimeBodyPart(InternetHeaders headers, byte[] content)- Create and return a MimeBodyPart object to represent a body part parsed
from the InputStream.
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BodyPart | getBodyPart(String CID)- Get the MimeBodyPart referred to by the given ContentID(CID).
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BodyPart | getBodyPart(int index)- Get the specified BodyPart.
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int | getCount()- * Return the number of enclosed BodyPart objects.
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protected void | parse()- Parse the InputStream from our DataSource, constructing the appropriate
MimeBodyParts.
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void | setSubType(String subtype)- Set the subtype.
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protected void | updateHeaders()- Update headers.
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void | writeTo(OutputStream os)- Iterates through all the parts and outputs each Mime part
separated by a boundary.
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addBodyPart, addBodyPart, getBodyPart, getContentType, getCount, getParent, removeBodyPart, removeBodyPart, setMultipartDataSource, setParent, writeTo |
ds
protected DataSource ds
The DataSource supplying our InputStream.
parsed
protected boolean parsed
Have we parsed the data from our InputStream yet?
Defaults to true; set to false when our constructor is given
a DataSource with an InputStream that we need to parse.
MimeMultipart
public MimeMultipart()
Default constructor.
An empty MimeMultipart object is created.
Its content type is set to "multipart/mixed".
A unique boundary string is generated and this string is set up
as the "boundary" parameter for the
contentType field.
MimeBodyParts may be added later.
MimeMultipart
public MimeMultipart(DataSource ds)
throws MessagingException Constructs a MimeMultipart object and its bodyparts from the given
DataSource.
This constructor handles as a special case the situation where the given
DataSource is a MultipartDataSource object. In this case, this method
just invokes the superclass(i.e., Multipart) constructor that takes a
MultipartDataSource object.
Otherwise, the DataSource is assumed to provide a MIME multipart byte
stream. The parsed flag is set to false. When the data for the body parts
are needed, the parser extracts the "boundary" parameter from the content
type of this DataSource, skips the 'preamble' and reads bytes till the
terminating boundary and creates MimeBodyParts for each part of the
stream.
ds - DataSource, can be a MultipartDataSource
MimeMultipart
public MimeMultipart(String subtype)
Construct a MimeMultipart object of the given subtype.
A unique boundary string is generated and this string is set up
as the "boundary" parameter for the
contentType field.
MimeBodyParts may be added later.
createInternetHeaders
protected InternetHeaders createInternetHeaders(InputStream is)
throws MessagingException Create and return an InternetHeaders object that loads the headers
from the given InputStream.
Subclasses can override this method to return a subclass
of InternetHeaders, if necessary.
This implementation simply constructs and returns an InternetHeaders
object.
is - the InputStream to read the headers from
createMimeBodyPart
protected MimeBodyPart createMimeBodyPart(InputStream is)
throws MessagingException Create and return a MimeBodyPart object to represent a body part parsed
from the InputStream.
Subclasses can override this method to return a subclass of
MimeBodyPart, if necessary. This implementation simply constructs and
returns a MimeBodyPart object.
is - InputStream containing the body part
createMimeBodyPart
protected MimeBodyPart createMimeBodyPart(InternetHeaders headers,
byte[] content)
throws MessagingException Create and return a MimeBodyPart object to represent a body part parsed
from the InputStream.
Subclasses can override this method to return a subclass of
MimeBodyPart, if necessary. This implementation simply constructs and
returns a MimeBodyPart object.
headers - the headers for the body partcontent - the content of the body part
getBodyPart
public BodyPart getBodyPart(String CID)
throws MessagingException Get the MimeBodyPart referred to by the given ContentID(CID).
Returns null if the part is not found.
CID - the ContentID of the desired part
getCount
public int getCount()
throws MessagingException * Return the number of enclosed BodyPart objects.
- getCount in interface Multipart
parse
protected void parse()
throws MessagingException Parse the InputStream from our DataSource, constructing the appropriate
MimeBodyParts.
The parsed flag is set to true, and if true on entry nothing is done.
This method is called by all other methods that need data for the body
parts, to make sure the data has been parsed.
setSubType
public void setSubType(String subtype)
throws MessagingException Set the subtype.
This method should be invoked only on a new MimeMultipart object
created by the client. The default subtype of such a multipart object
is "mixed".
subtype - Subtype
updateHeaders
protected void updateHeaders()
throws MessagingException Update headers.
The default implementation here just calls the
updateHeaders
method on each of its children BodyParts.
Note that the boundary parameter is already set up when a new and empty
MimeMultipart object is created.
This method is called when the
saveChanges method is
invoked on the Message object containing this Multipart.
This is typically done as part of the Message send process,
however note that a client is free to call it any number of times.
So if the header updating process is expensive for a specific
MimeMultipart subclass, then it might itself want to track whether
its internal state actually did change,
and do the header updating only if necessary.
writeTo
public void writeTo(OutputStream os)
throws IOException,
MessagingException Iterates through all the parts and outputs each Mime part
separated by a boundary.
- writeTo in interface Multipart