InternetHeaders.javaAPI DocGlassfish v2 API19329Mon May 14 15:28:50 BST 2007javax.mail.internet


public class InternetHeaders extends Object
InternetHeaders is a utility class that manages RFC822 style headers. Given an RFC822 format message stream, it reads lines until the blank line that indicates end of header. The input stream is positioned at the start of the body. The lines are stored within the object and can be extracted as either Strings or {@link javax.mail.Header} objects.

This class is mostly intended for service providers. MimeMessage and MimeBody use this class for holding their headers.

A note on RFC822 and MIME headers

RFC822 and MIME header fields must contain only US-ASCII characters. If a header contains non US-ASCII characters, it must be encoded as per the rules in RFC 2047. The MimeUtility class provided in this package can be used to to achieve this. Callers of the setHeader, addHeader, and addHeaderLine methods are responsible for enforcing the MIME requirements for the specified headers. In addition, these header fields must be folded (wrapped) before being sent if they exceed the line length limitation for the transport (1000 bytes for SMTP). Received headers may have been folded. The application is responsible for folding and unfolding headers as appropriate.

John Mani
Bill Shannon

Fields Summary
protected List
The actual list of Headers, including placeholder entries. Placeholder entries are Headers with a null value and are never seen by clients of the InternetHeaders class. Placeholder entries are used to keep track of the preferred order of headers. Headers are never actually removed from the list, they're converted into placeholder entries. New headers are added after existing headers of the same name (or before in the case of Received and Return-Path headers). If no existing header or placeholder for the header is found, new headers are added after the special placeholder with the name ":".
Constructors Summary
public InternetHeaders()
Create an empty InternetHeaders object. Placeholder entries are inserted to indicate the preferred order of headers.

   	headers = new ArrayList(40); 
	headers.add(new InternetHeader("Return-Path", null));
	headers.add(new InternetHeader("Received", null));
	headers.add(new InternetHeader("Resent-Date", null));
	headers.add(new InternetHeader("Resent-From", null));
	headers.add(new InternetHeader("Resent-Sender", null));
	headers.add(new InternetHeader("Resent-To", null));
	headers.add(new InternetHeader("Resent-Cc", null));
	headers.add(new InternetHeader("Resent-Bcc", null));
	headers.add(new InternetHeader("Resent-Message-Id", null));
	headers.add(new InternetHeader("Date", null));
	headers.add(new InternetHeader("From", null));
	headers.add(new InternetHeader("Sender", null));
	headers.add(new InternetHeader("Reply-To", null));
	headers.add(new InternetHeader("To", null));
	headers.add(new InternetHeader("Cc", null));
	headers.add(new InternetHeader("Bcc", null));
	headers.add(new InternetHeader("Message-Id", null));
	headers.add(new InternetHeader("In-Reply-To", null));
	headers.add(new InternetHeader("References", null));
	headers.add(new InternetHeader("Subject", null));
	headers.add(new InternetHeader("Comments", null));
	headers.add(new InternetHeader("Keywords", null));
	headers.add(new InternetHeader("Errors-To", null));
	headers.add(new InternetHeader("MIME-Version", null));
	headers.add(new InternetHeader("Content-Type", null));
	headers.add(new InternetHeader("Content-Transfer-Encoding", null));
	headers.add(new InternetHeader("Content-MD5", null));
	headers.add(new InternetHeader(":", null));
	headers.add(new InternetHeader("Content-Length", null));
	headers.add(new InternetHeader("Status", null));
public InternetHeaders(InputStream is)
Read and parse the given RFC822 message stream till the blank line separating the header from the body. The input stream is left positioned at the start of the body. The header lines are stored internally.

For efficiency, wrap a BufferedInputStream around the actual input stream and pass it as the parameter.

No placeholder entries are inserted; the original order of the headers is preserved.

is RFC822 input stream

   	headers = new ArrayList(40); 
Methods Summary
public voidaddHeader(java.lang.String name, java.lang.String value)
Add a header with the specified name and value to the header list.

The current implementation knows about the preferred order of most well-known headers and will insert headers in that order. In addition, it knows that Received headers should be inserted in reverse order (newest before oldest), and that they should appear at the beginning of the headers, preceeded only by a possible Return-Path header.

Note that RFC822 headers can only contain US-ASCII characters.

name header name
value header value

	int pos = headers.size();
	boolean addReverse =
	    name.equalsIgnoreCase("Received") ||
	if (addReverse)
	    pos = 0;
	for (int i = headers.size() - 1; i >= 0; i--) {
	    InternetHeader h = (InternetHeader)headers.get(i);
	    if (name.equalsIgnoreCase(h.getName())) {
		if (addReverse) {
		    pos = i;
		} else {
		    headers.add(i + 1, new InternetHeader(name, value));
	    // marker for default place to add new headers
	    if (h.getName().equals(":"))
		pos = i;
	headers.add(pos, new InternetHeader(name, value));
public voidaddHeaderLine(java.lang.String line)
Add an RFC822 header line to the header store. If the line starts with a space or tab (a continuation line), add it to the last header line in the list. Otherwise, append the new header line to the list.

Note that RFC822 headers can only contain US-ASCII characters

line raw RFC822 header line

	try {
	    char c = line.charAt(0);
	    if (c == ' " || c == '\t") {
		InternetHeader h =
		    (InternetHeader)headers.get(headers.size() - 1);
		h.line += "\r\n" + line;
	    } else
		headers.add(new InternetHeader(line));
	} catch (StringIndexOutOfBoundsException e) {
	    // line is empty, ignore it
	} catch (NoSuchElementException e) {
	    // XXX - vector is empty?
public java.util.EnumerationgetAllHeaderLines()
Return all the header lines as an Enumeration of Strings.

	return (getNonMatchingHeaderLines(null));
public java.util.EnumerationgetAllHeaders()
Return all the headers as an Enumeration of {@link javax.mail.Header} objects.

Header objects

	return (new matchEnum(headers, null, false, false));
public java.lang.String[]getHeader(java.lang.String name)
Return all the values for the specified header. The values are String objects. Returns null if no headers with the specified name exist.

name header name
array of header values, or null if none

	Iterator e = headers.iterator();
	// XXX - should we just step through in index order?
	List v = new ArrayList(); // accumulate return values

	while (e.hasNext()) {
	    InternetHeader h = (InternetHeader);
	    if (name.equalsIgnoreCase(h.getName()) && h.line != null) {
	if (v.size() == 0)
	    return (null);
	// convert List to an array for return
	String r[] = new String[v.size()];
	r = (String[])v.toArray(r);
	return (r);
public java.lang.StringgetHeader(java.lang.String name, java.lang.String 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. Returns null if no headers with the specified name exist.

name header name
delimiter delimiter
the value fields for all headers with this name, or null if none

	String s[] = getHeader(name);

	if (s == null)
	    return null;
	if ((s.length == 1) || delimiter == null)
	    return s[0];
	StringBuffer r = new StringBuffer(s[0]);
	for (int i = 1; i < s.length; i++) {
	return r.toString();
public java.util.EnumerationgetMatchingHeaderLines(java.lang.String[] names)
Return all matching header lines as an Enumeration of Strings.

	return (new matchEnum(headers, names, true, true));	
public java.util.EnumerationgetMatchingHeaders(java.lang.String[] names)
Return all matching {@link javax.mail.Header} objects.

matching Header objects

	return (new matchEnum(headers, names, true, false));
public java.util.EnumerationgetNonMatchingHeaderLines(java.lang.String[] names)
Return all non-matching header lines

	return (new matchEnum(headers, names, false, true));
public java.util.EnumerationgetNonMatchingHeaders(java.lang.String[] names)
Return all non-matching {@link javax.mail.Header} objects.

non-matching Header objects

	return (new matchEnum(headers, names, false, false));
public voidload( is)
Read and parse the given RFC822 message stream till the blank line separating the header from the body. Store the header lines inside this InternetHeaders object. The order of header lines is preserved.

Note that the header lines are added into this InternetHeaders object, so any existing headers in this object will not be affected. Headers are added to the end of the existing list of headers, in order.

is RFC822 input stream

	// Read header lines until a blank line. It is valid
	// to have BodyParts with no header lines.
	String line;
	LineInputStream lis = new LineInputStream(is);
	String prevline = null;	// the previous header line, as a string
	// a buffer to accumulate the header in, when we know it's needed
	StringBuffer lineBuffer = new StringBuffer();

	try {
	    //while ((line = lis.readLine()) != null) {
	    do {
		line = lis.readLine();
		if (line != null &&
			(line.startsWith(" ") || line.startsWith("\t"))) {
		    // continuation of header
		    if (prevline != null) {
			prevline = null;
		} else {
		    // new header
		    if (prevline != null)
		    else if (lineBuffer.length() > 0) {
			// store previous header first
		    prevline = line;
	    } while (line != null && line.length() > 0);
	} catch (IOException ioex) {
	    throw new MessagingException("Error in input stream", ioex);
public voidremoveHeader(java.lang.String name)
Remove all header entries that match the given name

name header name

	for (int i = 0; i < headers.size(); i++) {
	    InternetHeader h = (InternetHeader)headers.get(i);
	    if (name.equalsIgnoreCase(h.getName())) {
		h.line = null;
		//i--;    // have to look at i again
public voidsetHeader(java.lang.String name, java.lang.String value)
Change the first header line that matches name to have value, adding a new header if no existing header matches. Remove all matching headers but the first.

Note that RFC822 headers can only contain US-ASCII characters

name header name
value header value

	boolean found = false;

	for (int i = 0; i < headers.size(); i++) {
	    InternetHeader h = (InternetHeader)headers.get(i);
	    if (name.equalsIgnoreCase(h.getName())) {
		if (!found) {
		    int j;
		    if (h.line != null && (j = h.line.indexOf(':")) >= 0) {
			h.line = h.line.substring(0, j + 1) + " " + value;
			// preserves capitalization, spacing
		    } else {
			h.line = name + ": " + value;
		    found = true;
		} else {
		    i--;    // have to look at i again
	if (!found) {
	    addHeader(name, value);