File	Doc	Category	Size	Date	Package
HeaderTokenizer.java	API Doc	Glassfish v2 API	11459	Mon May 14 15:28:48 BST 2007	javax.mail.internet

HeaderTokenizer

• java.lang.Object

Fields Summary
private String	string
private boolean	skipComments
private String	delimiters
private int	currentPos
private int	maxPos
private int	nextPos
private int	peekPos
public static final String	RFC822 RFC822 specials
public static final String	MIME MIME specials
private static final Token	EOFToken

Constructors Summary
public HeaderTokenizer(String header, String delimiters, boolean skipComments) Constructor that takes a rfc822 style header. param header The rfc822 header to be tokenized param delimiters Set of delimiter characters to be used to delimit ATOMS. These are usually RFC822 or MIME param skipComments If true, comments are skipped and not returned as tokens string = (header == null) ? "" : header; // paranoia ?! this.skipComments = skipComments; this.delimiters = delimiters; currentPos = nextPos = peekPos = 0; maxPos = string.length();
public HeaderTokenizer(String header, String delimiters) Constructor. Comments are ignored and not returned as tokens param header The header that is tokenized param delimiters The delimiters to be used this(header, delimiters, true);
public HeaderTokenizer(String header) Constructor. The RFC822 defined delimiters - RFC822 - are used to delimit ATOMS. Also comments are skipped and not returned as tokens this(header, RFC822);

Methods Summary
private static java.lang.String	filterToken(java.lang.String s, int start, int end) StringBuffer sb = new StringBuffer(); char c; boolean gotEscape = false; boolean gotCR = false; for (int i = start; i < end; i++) { c = s.charAt(i); if (c == '\n" && gotCR) { // This LF is part of an unescaped // CRLF sequence (i.e, LWSP). Skip it. gotCR = false; continue; } gotCR = false; if (!gotEscape) { // Previous character was NOT '\' if (c == '\\") // skip this character gotEscape = true; else if (c == '\r") // skip this character gotCR = true; else // append this character sb.append(c); } else { // Previous character was '\'. So no need to // bother with any special processing, just // append this character sb.append(c); gotEscape = false; } } return sb.toString();
private javax.mail.internet.HeaderTokenizer$Token	getNext() // If we're already at end of string, return EOF if (currentPos >= maxPos) return EOFToken; // Skip white-space, position currentPos beyond the space if (skipWhiteSpace() == Token.EOF) return EOFToken; char c; int start; boolean filter = false; c = string.charAt(currentPos); // Check or Skip comments and position currentPos // beyond the comment while (c == '(") { // Parsing comment .. int nesting; for (start = ++currentPos, nesting = 1; nesting > 0 && currentPos < maxPos; currentPos++) { c = string.charAt(currentPos); if (c == '\\") { // Escape sequence currentPos++; // skip the escaped character filter = true; } else if (c == '\r") filter = true; else if (c == '(") nesting++; else if (c == ')") nesting--; } if (nesting != 0) throw new ParseException("Unbalanced comments"); if (!skipComments) { // Return the comment, if we are asked to. // Note that the comment start & end markers are ignored. String s; if (filter) // need to go thru the token again. s = filterToken(string, start, currentPos-1); else s = string.substring(start,currentPos-1); return new Token(Token.COMMENT, s); } // Skip any whitespace after the comment. if (skipWhiteSpace() == Token.EOF) return EOFToken; c = string.charAt(currentPos); } // Check for quoted-string and position currentPos // beyond the terminating quote if (c == '"") { for (start = ++currentPos; currentPos < maxPos; currentPos++) { c = string.charAt(currentPos); if (c == '\\") { // Escape sequence currentPos++; filter = true; } else if (c == '\r") filter = true; else if (c == '"") { currentPos++; String s; if (filter) s = filterToken(string, start, currentPos-1); else s = string.substring(start,currentPos-1); return new Token(Token.QUOTEDSTRING, s); } } throw new ParseException("Unbalanced quoted string"); } // Check for SPECIAL or CTL if (c < 040 || c >= 0177 || delimiters.indexOf(c) >= 0) { currentPos++; // re-position currentPos char ch[] = new char[1]; ch[0] = c; return new Token((int)c, new String(ch)); } // Check for ATOM for (start = currentPos; currentPos < maxPos; currentPos++) { c = string.charAt(currentPos); // ATOM is delimited by either SPACE, CTL, "(", <"> // or the specified SPECIALS if (c < 040 || c >= 0177 || c == '(" || c == ' " || c == '"" || delimiters.indexOf(c) >= 0) break; } return new Token(Token.ATOM, string.substring(start, currentPos));
public java.lang.String	getRemainder() Return the rest of the Header. return String rest of header. null is returned if we are already at end of header return string.substring(nextPos);
public javax.mail.internet.HeaderTokenizer$Token	next() Parses the next token from this String. Clients sit in a loop calling next() to parse successive tokens until an EOF Token is returned. return the next Token exception ParseException if the parse fails Token tk; currentPos = nextPos; // setup currentPos tk = getNext(); nextPos = peekPos = currentPos; // update currentPos and peekPos return tk;
public javax.mail.internet.HeaderTokenizer$Token	peek() Peek at the next token, without actually removing the token from the parse stream. Invoking this method multiple times will return successive tokens, until next() is called. return the next Token exception ParseException if the parse fails Token tk; currentPos = peekPos; // setup currentPos tk = getNext(); peekPos = currentPos; // update peekPos return tk;
private int	skipWhiteSpace() char c; for (; currentPos < maxPos; currentPos++) if (((c = string.charAt(currentPos)) != ' ") && (c != '\t") && (c != '\r") && (c != '\n")) return currentPos; return Token.EOF;