since: JavaMail - 1.2

 public MimeBodyPart() 
{
	super();
	headers = new InternetHeaders();
}

An empty MimeBodyPart object is created. This body part maybe filled in by a client constructing a multipart message.

 public MimeBodyPart(InputStream is) throws MessagingException 
{
	if (!(is instanceof ByteArrayInputStream) &&
	    !(is instanceof BufferedInputStream) &&
	    !(is instanceof SharedInputStream))
	    is = new BufferedInputStream(is);
	headers = new InternetHeaders(is);
	if (is instanceof SharedInputStream) {
	    SharedInputStream sis = (SharedInputStream)is;
	    contentStream = sis.newStream(sis.getPosition(), -1);
	} else {
	    try {
		content = ASCIIUtility.getBytes(is);
	    } catch (IOException ioex) {
		throw new MessagingException("Error reading input stream", ioex);
	    }
	}
}

Constructs a MimeBodyPart by reading and parsing the data from the specified input stream. The parser consumes data till the end of the given input stream. The input stream must start at the beginning of a valid MIME body part and must terminate at the end of that body part.

Note that the "boundary" string that delimits body parts must not be included in the input stream. The intention is that the MimeMultipart parser will extract each body part's bytes from a multipart stream and feed them into this constructor, without the delimiter strings.

Parameters:

is - the body part Input Stream

 public MimeBodyPart(InternetHeaders headers,
    byte[] content) throws MessagingException 
{
	super();
	this.headers = headers;
	this.content = content;
}

Constructs a MimeBodyPart using the given header and content bytes.

Used by providers.

Parameters:

headers - The header of this part

content - bytes representing the body of this part.

 public  void addHeader(String name,
    String value) throws MessagingException 
{
	headers.addHeader(name, value);
}

Add this value to the existing values for this header_name. Note that RFC 822 headers must contain only US-ASCII characters, so a header that contains non US-ASCII characters must be encoded as per the rules of RFC 2047.

 public  void addHeaderLine(String line) throws MessagingException 
{
	headers.addHeaderLine(line);
}

Add a header line to this body part

 public  void attachFile(File file) throws IOException, MessagingException 
{
    	FileDataSource fds = new FileDataSource(file);   	
        this.setDataHandler(new DataHandler(fds));
        this.setFileName(fds.getName());
}

Use the specified file to provide the data for this part. The simple file name is used as the file name for this part and the data in the file is used as the data for this part. The encoding will be chosen appropriately for the file data.

 public  void attachFile(String file) throws IOException, MessagingException 
{
    	File f = new File(file);
    	attachFile(f);
}

Use the specified file to provide the data for this part. The simple file name is used as the file name for this part and the data in the file is used as the data for this part. The encoding will be chosen appropriately for the file data.

 public Enumeration getAllHeaderLines() throws MessagingException 
{
  	return headers.getAllHeaderLines();
}

Get all header lines as an Enumeration of Strings. A Header line is a raw RFC 822 header line, containing both the "name" and "value" field.

 public Enumeration getAllHeaders() throws MessagingException 
{
	return headers.getAllHeaders();
}

Return all the headers from this Message as an Enumeration of Header objects.

 public Object getContent() throws IOException, MessagingException 
{
	if (cachedContent != null)
	    return cachedContent;
	Object c;
	try {
	    c = getDataHandler().getContent();
	} catch (FolderClosedIOException fex) {
	    throw new FolderClosedException(fex.getFolder(), fex.getMessage());
	} catch (MessageRemovedIOException mex) {
	    throw new MessageRemovedException(mex.getMessage());
	}
	if (cacheMultipart &&
		(c instanceof Multipart || c instanceof Message) &&
		(content != null || contentStream != null)) {
	    cachedContent = c;
	}
	return c;
}

Return the content as a Java object. The type of the object returned is of course dependent on the content itself. For example, the native format of a text/plain content is usually a String object. The native format for a "multipart" content is always a Multipart subclass. For content types that are unknown to the DataHandler system, an input stream is returned as the content.

This implementation obtains the content from the DataHandler. That is, it invokes getDataHandler().getContent(); If the content is a Multipart or Message object and was created by parsing a stream, the object is cached and returned in subsequent calls so that modifications to the content will not be lost.

 public String getContentID() throws MessagingException 
{
	return getHeader("Content-Id", null);
}

Returns the value of the "Content-ID" header field. Returns null if the field is unavailable or its value is absent.

This implementation uses getHeader(name) to obtain the requisite header field.

 public String[] getContentLanguage() throws MessagingException 
{
	return getContentLanguage(this);
}

Get the languages specified in the Content-Language header of this MimePart. The Content-Language header is defined by RFC 1766. Returns null if this header is not available or its value is absent.

This implementation uses getHeader(name) to obtain the requisite header field.

 static String[] getContentLanguage(MimePart part) throws MessagingException 
{
	String s = part.getHeader("Content-Language", null);
	if (s == null)
	    return null;
	// Tokenize the header to obtain the Language-tags (skip comments)
	HeaderTokenizer h = new HeaderTokenizer(s, HeaderTokenizer.MIME);
	Vector v = new Vector();
	HeaderTokenizer.Token tk;
	int tkType;
	while (true) {
	    tk = h.next(); // get a language-tag
	    tkType = tk.getType();
	    if (tkType == HeaderTokenizer.Token.EOF)
		break; // done
	    else if (tkType == HeaderTokenizer.Token.ATOM)
		v.addElement(tk.getValue());
	    else // invalid token, skip it.
		continue;
	}
	if (v.size() == 0)
	    return null;
	String[] language = new String[v.size()];
	v.copyInto(language);
	return language;
}

 public String getContentMD5() throws MessagingException 
{
	return getHeader("Content-MD5", null);
}

Return the value of the "Content-MD5" header field. Returns null if this field is unavailable or its value is absent.

This implementation uses getHeader(name) to obtain the requisite header field.

 protected InputStream getContentStream() throws MessagingException 
{
	if (contentStream != null)
	    return ((SharedInputStream)contentStream).newStream(0, -1);
	if (content != null)
	    return new ByteArrayInputStream(content);
	throw new MessagingException("No content");
}

Produce the raw bytes of the content. This method is used when creating a DataHandler object for the content. Subclasses that can provide a separate input stream for just the Part content might want to override this method.

 public String getContentType() throws MessagingException 
{
	String s = getHeader("Content-Type", null);
	if (s == null)
	    s = "text/plain";
	return s;
}

Returns the value of the RFC 822 "Content-Type" header field. This represents the content type of the content of this body part. This value must not be null. If this field is unavailable, "text/plain" should be returned.

This implementation uses getHeader(name) to obtain the requisite header field.

 public DataHandler getDataHandler() throws MessagingException 
{
	if (dh == null)
	    dh = new DataHandler(new MimePartDataSource(this));
	return dh;
}

Return a DataHandler for this body part's content.

The implementation provided here works just like the the implementation in MimeMessage.

 public String getDescription() throws MessagingException 
{
	return getDescription(this);
}

Returns the "Content-Description" header field of this body part. This typically associates some descriptive information with this part. Returns null if this field is unavailable or its value is absent.

If the Content-Description field is encoded as per RFC 2047, it is decoded and converted into Unicode. If the decoding or conversion fails, the raw data is returned as is.

This implementation uses getHeader(name) to obtain the requisite header field.

 static String getDescription(MimePart part) throws MessagingException 
{
	String rawvalue = part.getHeader("Content-Description", null);
	if (rawvalue == null)
	    return null;
	try {
	    return MimeUtility.decodeText(MimeUtility.unfold(rawvalue));
	} catch (UnsupportedEncodingException ex) {
	    return rawvalue;
	}
}

 public String getDisposition() throws MessagingException 
{
	return getDisposition(this);
}

Returns the value of the "Content-Disposition" header field. This represents the disposition of this part. The disposition describes how the part should be presented to the user.

If the Content-Disposition field is unavailable, null is returned.

This implementation uses getHeader(name) to obtain the requisite header field.

 static String getDisposition(MimePart part) throws MessagingException 
{
	String s = part.getHeader("Content-Disposition", null);
	if (s == null)
	    return null;
	ContentDisposition cd = new ContentDisposition(s);
	return cd.getDisposition();
}

 public String getEncoding() throws MessagingException 
{
	return getEncoding(this);
}

Returns the content transfer encoding from the "Content-Transfer-Encoding" header field. Returns null if the header is unavailable or its value is absent.

This implementation uses getHeader(name) to obtain the requisite header field.

 static String getEncoding(MimePart part) throws MessagingException 
{
	String s = part.getHeader("Content-Transfer-Encoding", null);
	if (s == null)
	    return null;
	s = s.trim();	// get rid of trailing spaces
	// quick check for known values to avoid unnecessary use
	// of tokenizer.
	if (s.equalsIgnoreCase("7bit") || s.equalsIgnoreCase("8bit") ||
		s.equalsIgnoreCase("quoted-printable") ||
		s.equalsIgnoreCase("binary") ||
		s.equalsIgnoreCase("base64"))
	    return s;
	// Tokenize the header to obtain the encoding (skip comments)
	HeaderTokenizer h = new HeaderTokenizer(s, HeaderTokenizer.MIME);
	HeaderTokenizer.Token tk;
	int tkType;
	for (;;) {
	    tk = h.next(); // get a token
	    tkType = tk.getType();
	    if (tkType == HeaderTokenizer.Token.EOF)
		break; // done
	    else if (tkType == HeaderTokenizer.Token.ATOM)
		return tk.getValue();
	    else // invalid token, skip it.
		continue;
	}
	return s;
}

 public String getFileName() throws MessagingException 
{
	return getFileName(this);
}

Get the filename associated with this body part.

Returns the value of the "filename" parameter from the "Content-Disposition" header field of this body part. If its not available, returns the value of the "name" parameter from the "Content-Type" header field of this body part. Returns null if both are absent.

If the mail.mime.encodefilename System property is set to true, the MimeUtility.decodeText method will be used to decode the filename. While such encoding is not supported by the MIME spec, many mailers use this technique to support non-ASCII characters in filenames. The default value of this property is false.

 static String getFileName(MimePart part) throws MessagingException 
{
	String filename = null;
	String s = part.getHeader("Content-Disposition", null);
	if (s != null) {
	    // Parse the header ..
	    ContentDisposition cd = new ContentDisposition(s);
	    filename = cd.getParameter("filename");
	}
	if (filename == null) {
	    // Still no filename ? Try the "name" ContentType parameter
	    s = part.getHeader("Content-Type", null);
	    if (s != null) {
		try {
		    ContentType ct = new ContentType(s);
		    filename = ct.getParameter("name");
		} catch (ParseException pex) { }	// ignore it
	    }
	}
	if (decodeFileName && filename != null) {
	    try {
		filename = MimeUtility.decodeText(filename);
	    } catch (UnsupportedEncodingException ex) {
		throw new MessagingException("Can't decode filename", ex);
	    }
	}
	return filename;
}

 public String[] getHeader(String name) throws MessagingException 
{
	return headers.getHeader(name);
}

Get all the headers for this header_name. Note that certain headers may be encoded as per RFC 2047 if they contain non US-ASCII characters and these should be decoded.

 public String getHeader(String name,
    String delimiter) throws MessagingException 
{
	return headers.getHeader(name, delimiter);
}

Get all the headers for this header name, returned as a single String, with headers separated by the delimiter. If the delimiter is null, only the first header is returned.

 public InputStream getInputStream() throws IOException, MessagingException 
{
	return getDataHandler().getInputStream();
}

Return a decoded input stream for this body part's "content".

This implementation obtains the input stream from the DataHandler. That is, it invokes getDataHandler().getInputStream();

 public int getLineCount() throws MessagingException 
{
	return -1;
}

Return the number of lines for the content of this Part. Return -1 if this number cannot be determined.

Note that this number may not be an exact measure of the content length and may or may not account for any transfer encoding of the content.

This implementation returns -1.

 public Enumeration getMatchingHeaderLines(String[] names) throws MessagingException 
{
	return headers.getMatchingHeaderLines(names);
}

Get matching header lines as an Enumeration of Strings. A Header line is a raw RFC 822 header line, containing both the "name" and "value" field.

 public Enumeration getMatchingHeaders(String[] names) throws MessagingException 
{
	return headers.getMatchingHeaders(names);
}

Return matching headers from this Message as an Enumeration of Header objects.

 public Enumeration getNonMatchingHeaderLines(String[] names) throws MessagingException 
{
	return headers.getNonMatchingHeaderLines(names);
}

Get non-matching header lines as an Enumeration of Strings. A Header line is a raw RFC 822 header line, containing both the "name" and "value" field.

 public Enumeration getNonMatchingHeaders(String[] names) throws MessagingException 
{
	return headers.getNonMatchingHeaders(names);
}

Return non-matching headers from this Message as an Enumeration of Header objects.

 public InputStream getRawInputStream() throws MessagingException 
{
	return getContentStream();
}

Return an InputStream to the raw data with any Content-Transfer-Encoding intact. This method is useful if the "Content-Transfer-Encoding" header is incorrect or corrupt, which would prevent the getInputStream method or getContent method from returning the correct data. In such a case the application may use this method and attempt to decode the raw data itself.

This implementation simply calls the getContentStream method.

 public int getSize() throws MessagingException 
{
	if (content != null)
	    return content.length;
	if (contentStream != null) {
	    try {
		int size = contentStream.available();
		// only believe the size if it's greate than zero, since zero
		// is the default returned by the InputStream class itself
		if (size  > 0)
		    return size;
	    } catch (IOException ex) {
		// ignore it
	    }
	}
	return -1;
}

Return the size of the content of this body part in bytes. Return -1 if the size cannot be determined.

Note that this number may not be an exact measure of the content size and may or may not account for any transfer encoding of the content.

This implementation returns the size of the content array (if not null), or, if contentStream is not null, and the available method returns a positive number, it returns that number as the size. Otherwise, it returns -1.

 static  void invalidateContentHeaders(MimePart part) throws MessagingException 
{
	part.removeHeader("Content-Type");
	part.removeHeader("Content-Transfer-Encoding");
}

 public boolean isMimeType(String mimeType) throws MessagingException 
{
	return isMimeType(this, mimeType);
}

Is this Part of the specified MIME type? This method compares only the primaryType and subType. The parameters of the content types are ignored.

For example, this method will return true when comparing a Part of content type "text/plain" with "text/plain; charset=foobar".

If the subType of mimeType is the special character '*', then the subtype is ignored during the comparison.

 static boolean isMimeType(MimePart part,
    String mimeType) throws MessagingException 
{
	// XXX - lots of room for optimization here!
	try {
	    ContentType ct = new ContentType(part.getContentType());
	    return ct.match(mimeType);
	} catch (ParseException ex) {
	    return part.getContentType().equalsIgnoreCase(mimeType);
	}
}

 public  void removeHeader(String name) throws MessagingException 
{
	headers.removeHeader(name);
}

Remove all headers with this name.

 public  void saveFile(File file) throws IOException, MessagingException 
{
    	OutputStream out = null;
        InputStream in = null;
        try {
	    out = new BufferedOutputStream(new FileOutputStream(file));
	    in = this.getInputStream();
	    byte[] buf = new byte[8192];
	    int len;
	    while ((len = in.read(buf))  > 0)
		out.write(buf, 0, len); 
        } finally {
	    // close streams, but don't mask original exception, if any
	    try {
		if (in != null)
		    in.close();
	    } catch (IOException ex) { }
	    try {
		if (out != null)
		    out.close();
	    } catch (IOException ex) { }
        }
}

Save the contents of this part in the specified file. The content is decoded and saved, without any of the MIME headers.

 public  void saveFile(String file) throws IOException, MessagingException 
{
    	File f = new File(file);
    	saveFile(f);
}

Save the contents of this part in the specified file. The content is decoded and saved, without any of the MIME headers.

 public  void setContent(Multipart mp) throws MessagingException 
{
	setDataHandler(new DataHandler(mp, mp.getContentType()));
	mp.setParent(this);
}

This method sets the body part's content to a Multipart object.

 public  void setContent(Object o,
    String type) throws MessagingException 
{
	if (o instanceof Multipart) {
	    setContent((Multipart)o);
	} else {
	    setDataHandler(new DataHandler(o, type));
	}
}

A convenience method for setting this body part's content.

The content is wrapped in a DataHandler object. Note that a DataContentHandler class for the specified type should be available to the JavaMail implementation for this to work right. That is, to do setContent(foobar, "application/x-foobar"), a DataContentHandler for "application/x-foobar" should be installed. Refer to the Java Activation Framework for more information.

 public  void setContentID(String cid) throws MessagingException 
{
	if (cid == null)
	    removeHeader("Content-ID");
	else
	    setHeader("Content-ID", cid);
}

Set the "Content-ID" header field of this body part. If the cid parameter is null, any existing "Content-ID" is removed.

 public  void setContentLanguage(String[] languages) throws MessagingException 
{
	setContentLanguage(this, languages);
}

Set the Content-Language header of this MimePart. The Content-Language header is defined by RFC 1766.

 static  void setContentLanguage(MimePart part,
    String[] languages) throws MessagingException 
{
	StringBuffer sb = new StringBuffer(languages[0]);
	for (int i = 1; i <  languages.length; i++)
	    sb.append(',").append(languages[i]);
	part.setHeader("Content-Language", sb.toString());
}

 public  void setContentMD5(String md5) throws MessagingException 
{
	setHeader("Content-MD5", md5);
}

Set the "Content-MD5" header field of this body part.

 public  void setDataHandler(DataHandler dh) throws MessagingException 
{
	this.dh = dh;
	cachedContent = null;
	MimeBodyPart.invalidateContentHeaders(this);
}

This method provides the mechanism to set this body part's content. The given DataHandler object should wrap the actual content.

 public  void setDescription(String description) throws MessagingException 
{
	setDescription(description, null);
}

Set the "Content-Description" header field for this body part. If the description parameter is null, then any existing "Content-Description" fields are removed.

If the description contains non US-ASCII characters, it will be encoded using the platform's default charset. If the description contains only US-ASCII characters, no encoding is done and it is used as is.

Note that if the charset encoding process fails, a MessagingException is thrown, and an UnsupportedEncodingException is included in the chain of nested exceptions within the MessagingException.

 public  void setDescription(String description,
    String charset) throws MessagingException 
{
	setDescription(this, description, charset);
}

Set the "Content-Description" header field for this body part. If the description parameter is null, then any existing "Content-Description" fields are removed.

If the description contains non US-ASCII characters, it will be encoded using the specified charset. If the description contains only US-ASCII characters, no encoding is done and it is used as is.

Note that if the charset encoding process fails, a MessagingException is thrown, and an UnsupportedEncodingException is included in the chain of nested exceptions within the MessagingException.

 static  void setDescription(MimePart part,
    String description,
    String charset) throws MessagingException 
{
	if (description == null) {
	    part.removeHeader("Content-Description");
	    return;
	}
	try {
	    part.setHeader("Content-Description", MimeUtility.fold(21,
		MimeUtility.encodeText(description, charset, null)));
	} catch (UnsupportedEncodingException uex) {
	    throw new MessagingException("Encoding error", uex);
	}
}

 public  void setDisposition(String disposition) throws MessagingException 
{
	setDisposition(this, disposition);
}

Set the "Content-Disposition" header field of this body part. If the disposition is null, any existing "Content-Disposition" header field is removed.

 static  void setDisposition(MimePart part,
    String disposition) throws MessagingException 
{
	if (disposition == null)
	    part.removeHeader("Content-Disposition");
	else {
	    String s = part.getHeader("Content-Disposition", null);
	    if (s != null) { 
		/* A Content-Disposition header already exists ..
		 *
		 * Override disposition, but attempt to retain 
		 * existing disposition parameters
		 */
		ContentDisposition cd = new ContentDisposition(s);
		cd.setDisposition(disposition);
		disposition = cd.toString();
	    }
	    part.setHeader("Content-Disposition", disposition);
	}
}

 static  void setEncoding(MimePart part,
    String encoding) throws MessagingException 
{
	part.setHeader("Content-Transfer-Encoding", encoding);
}

 public  void setFileName(String filename) throws MessagingException 
{
	setFileName(this, filename);
}

Set the filename associated with this body part, if possible.

Sets the "filename" parameter of the "Content-Disposition" header field of this body part. For compatibility with older mailers, the "name" parameter of the "Content-Type" header is also set.

If the mail.mime.encodefilename System property is set to true, the MimeUtility.encodeText method will be used to encode the filename. While such encoding is not supported by the MIME spec, many mailers use this technique to support non-ASCII characters in filenames. The default value of this property is false.

 static  void setFileName(MimePart part,
    String name) throws MessagingException 
{
	if (encodeFileName && name != null) {
	    try {
		name = MimeUtility.encodeText(name);
	    } catch (UnsupportedEncodingException ex) {
		throw new MessagingException("Can't encode filename", ex);
	    }
	}
	// Set the Content-Disposition "filename" parameter
	String s = part.getHeader("Content-Disposition", null);
	ContentDisposition cd = 
		new ContentDisposition(s == null ? Part.ATTACHMENT : s);
	cd.setParameter("filename", name);
	part.setHeader("Content-Disposition", cd.toString());
	/*
	 * Also attempt to set the Content-Type "name" parameter,
	 * to satisfy ancient MUAs.  XXX - This is not RFC compliant.
	 */
	if (setContentTypeFileName) {
	    s = part.getHeader("Content-Type", null);
	    if (s != null) {
		try {
		    ContentType cType = new ContentType(s);
		    cType.setParameter("name", name);
		    part.setHeader("Content-Type", cType.toString());
		} catch (ParseException pex) { }	// ignore it
	    }
	}
}

 public  void setHeader(String name,
    String value) throws MessagingException 
{
	headers.setHeader(name, value);
}

Set the value for this header_name. Replaces all existing header values with this new value. Note that RFC 822 headers must contain only US-ASCII characters, so a header that contains non US-ASCII characters must be encoded as per the rules of RFC 2047.

 public  void setText(String text) throws MessagingException 
{
	setText(text, null);
}

Convenience method that sets the given String as this part's content, with a MIME type of "text/plain". If the string contains non US-ASCII characters, it will be encoded using the platform's default charset. The charset is also used to set the "charset" parameter.

Note that there may be a performance penalty if text is large, since this method may have to scan all the characters to determine what charset to use.

If the charset is already known, use the setText method that takes the charset parameter.

 public  void setText(String text,
    String charset) throws MessagingException 
{
	setText(this, text, charset, "plain");
}

Convenience method that sets the given String as this part's content, with a MIME type of "text/plain" and the specified charset. The given Unicode string will be charset-encoded using the specified charset. The charset is also used to set the "charset" parameter.

 public  void setText(String text,
    String charset,
    String subtype) throws MessagingException 
{
	setText(this, text, charset, subtype);
}

Convenience method that sets the given String as this part's content, with a primary MIME type of "text" and the specified MIME subtype. The given Unicode string will be charset-encoded using the specified charset. The charset is also used to set the "charset" parameter.

 static  void setText(MimePart part,
    String text,
    String charset,
    String subtype) throws MessagingException 
{
	if (charset == null) {
	    if (MimeUtility.checkAscii(text) != MimeUtility.ALL_ASCII)
		charset = MimeUtility.getDefaultMIMECharset();
	    else
		charset = "us-ascii";
	}
	// XXX - should at least ensure that subtype is an atom
	part.setContent(text, "text/" + subtype + "; charset=" +
			MimeUtility.quote(charset, HeaderTokenizer.MIME));
}

 protected  void updateHeaders() throws MessagingException 
{
	updateHeaders(this);
	/*
	 * If we've cached a Multipart or Message object then
	 * we're now committed to using this instance of the
	 * object and we discard any stream data used to create
	 * this object.
	 */
	if (cachedContent != null) {
	    dh = new DataHandler(cachedContent, getContentType());
	    cachedContent = null;
	    content = null;
	    if (contentStream != null) {
		try {
		    contentStream.close();
		} catch (IOException ioex) { }	// nothing to do
	    }
	    contentStream = null;
	}
}

Examine the content of this body part and update the appropriate MIME headers. Typical headers that get set here are Content-Type and Content-Transfer-Encoding. Headers might need to be updated in two cases:
- A message being crafted by a mail application will certainly need to activate this method at some point to fill up its internal headers.
- A message read in from a Store will have obtained all its headers from the store, and so doesn't need this. However, if this message is editable and if any edits have been made to either the content or message structure, we might need to resync our headers.
In both cases this method is typically called by the Message.saveChanges method.

 static  void updateHeaders(MimePart part) throws MessagingException 
{
	DataHandler dh = part.getDataHandler();
	if (dh == null) // Huh ?
	    return;
	try {
	    String type = dh.getContentType();
	    boolean composite = false;
	    boolean needCTHeader = part.getHeader("Content-Type") == null;
	    ContentType cType = new ContentType(type);
	    if (cType.match("multipart/*")) {
		// If multipart, recurse
		composite = true;
		Object o;
		if (part instanceof MimeBodyPart) {
		    MimeBodyPart mbp = (MimeBodyPart)part;
		    o = mbp.cachedContent != null ?
				mbp.cachedContent : dh.getContent();
		} else if (part instanceof MimeMessage) {
		    MimeMessage msg = (MimeMessage)part;
		    o = msg.cachedContent != null ?
				msg.cachedContent : dh.getContent();
		} else
		    o = dh.getContent();
		if (o instanceof MimeMultipart)
		    ((MimeMultipart)o).updateHeaders();
		else
		    throw new MessagingException("MIME part of type \"" +
			type + "\" contains object of type " +
			o.getClass().getName() + " instead of MimeMultipart");
	    } else if (cType.match("message/rfc822")) {
		composite = true;
		// XXX - call MimeMessage.updateHeaders()?
	    }
	    // Content-Transfer-Encoding, but only if we don't
	    // already have one
	    if (!composite) {	// not allowed on composite parts
		if (part.getHeader("Content-Transfer-Encoding") == null)
		    setEncoding(part, MimeUtility.getEncoding(dh));
		if (needCTHeader && setDefaultTextCharset &&
			cType.match("text/*") &&
			cType.getParameter("charset") == null) {
		    /*
		     * Set a default charset for text parts.
		     * We really should examine the data to determine
		     * whether or not it's all ASCII, but that's too
		     * expensive so we make an assumption:  If we
		     * chose 7bit encoding for this data, it's probably
		     * ASCII.  (MimeUtility.getEncoding will choose
		     * 7bit only in this case, but someone might've
		     * set the Content-Transfer-Encoding header manually.)
		     */
		    String charset;
		    String enc = part.getEncoding();
		    if (enc != null && enc.equalsIgnoreCase("7bit"))
			charset = "us-ascii";
		    else
			charset = MimeUtility.getDefaultMIMECharset();
		    cType.setParameter("charset", charset);
		    type = cType.toString();
		}
	    }
	    // Now, let's update our own headers ...
	    // Content-type, but only if we don't already have one
	    if (needCTHeader) {
		/*
		 * Pull out "filename" from Content-Disposition, and
		 * use that to set the "name" parameter. This is to
		 * satisfy older MUAs (DtMail, Roam and probably
		 * a bunch of others).
		 */
		String s = part.getHeader("Content-Disposition", null);
		if (s != null) {
		    // Parse the header ..
		    ContentDisposition cd = new ContentDisposition(s);
		    String filename = cd.getParameter("filename");
		    if (filename != null) {
			cType.setParameter("name", filename);
			type = cType.toString();
		    }
		}
		part.setHeader("Content-Type", type);
	    }
	} catch (IOException ex) {
	    throw new MessagingException("IOException updating headers", ex);
	}
}

 public  void writeTo(OutputStream os) throws IOException, MessagingException 
{
	writeTo(this, os, null);
}

Output the body part as an RFC 822 format stream.

 static  void writeTo(MimePart part,
    OutputStream os,
    String[] ignoreList) throws IOException, MessagingException 
{
	// see if we already have a LOS
	LineOutputStream los = null;
	if (os instanceof LineOutputStream) {
	    los = (LineOutputStream) os;
	} else {
	    los = new LineOutputStream(os);
	}
	// First, write out the header
	Enumeration hdrLines = part.getNonMatchingHeaderLines(ignoreList);
	while (hdrLines.hasMoreElements())
	    los.writeln((String)hdrLines.nextElement());
	// The CRLF separator between header and content
	los.writeln();
	// Finally, the content. Encode if required.
	// XXX: May need to account for ESMTP ?
	os = MimeUtility.encode(os, part.getEncoding());
	part.getDataHandler().writeTo(os);
	os.flush(); // Needed to complete encoding
}