| /* |
| * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @(#)HeaderTokenizer.java 1.9 02/03/27 |
| */ |
| |
| |
| |
| package com.sun.xml.internal.messaging.saaj.packaging.mime.internet; |
| |
| |
| /** |
| * This class tokenizes RFC822 and MIME headers into the basic |
| * symbols specified by RFC822 and MIME. <p> |
| * |
| * This class handles folded headers (ie headers with embedded |
| * CRLF SPACE sequences). The folds are removed in the returned |
| * tokens. |
| * |
| * @version 1.9, 02/03/27 |
| * @author John Mani |
| */ |
| |
| public class HeaderTokenizer { |
| |
| /** |
| * The Token class represents tokens returned by the |
| * HeaderTokenizer. |
| */ |
| public static class Token { |
| |
| private int type; |
| private String value; |
| |
| /** |
| * Token type indicating an ATOM. |
| */ |
| public static final int ATOM = -1; |
| |
| /** |
| * Token type indicating a quoted string. The value |
| * field contains the string without the quotes. |
| */ |
| public static final int QUOTEDSTRING = -2; |
| |
| /** |
| * Token type indicating a comment. The value field |
| * contains the comment string without the comment |
| * start and end symbols. |
| */ |
| public static final int COMMENT = -3; |
| |
| /** |
| * Token type indicating end of input. |
| */ |
| public static final int EOF = -4; |
| |
| /** |
| * Constructor. |
| * @param type Token type |
| * @param value Token value |
| */ |
| public Token(int type, String value) { |
| this.type = type; |
| this.value = value; |
| } |
| |
| /** |
| * Return the type of the token. If the token represents a |
| * delimiter or a control character, the type is that character |
| * itself, converted to an integer. Otherwise, it's value is |
| * one of the following: |
| * <ul> |
| * <li><code>ATOM</code> A sequence of ASCII characters |
| * delimited by either SPACE, CTL, "(", <"> or the |
| * specified SPECIALS</li> |
| * <li><code>QUOTEDSTRING</code> A sequence of ASCII characters |
| * within quotes</li> |
| * <li><code>COMMENT</code> A sequence of ASCII characters |
| * within "(" and ")".</li> |
| * <li><code>EOF</code> End of header</li> |
| * </ul> |
| * @return type |
| */ |
| public int getType() { |
| return type; |
| } |
| |
| /** |
| * Returns the value of the token just read. When the current |
| * token is a quoted string, this field contains the body of the |
| * string, without the quotes. When the current token is a comment, |
| * this field contains the body of the comment. |
| * |
| * @return token value |
| */ |
| public String getValue() { |
| return value; |
| } |
| } |
| |
| private String string; // the string to be tokenized |
| private boolean skipComments; // should comments be skipped ? |
| private String delimiters; // delimiter string |
| private int currentPos; // current parse position |
| private int maxPos; // string length |
| private int nextPos; // track start of next Token for next() |
| private int peekPos; // track start of next Token for peek() |
| |
| /** |
| * RFC822 specials |
| */ |
| public final static String RFC822 = "()<>@,;:\\\"\t .[]"; |
| |
| /** |
| * MIME specials |
| */ |
| public final static String MIME = "()<>@,;:\\\"\t []/?="; |
| |
| // The EOF Token |
| private final static Token EOFToken = new Token(Token.EOF, null); |
| |
| /** |
| * 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 <code>RFC822</code> or |
| * <code>MIME</code> |
| * @param skipComments If true, comments are skipped and |
| * not returned as tokens |
| */ |
| public HeaderTokenizer(String header, String delimiters, |
| boolean skipComments) { |
| string = (header == null) ? "" : header; // paranoia ?! |
| this.skipComments = skipComments; |
| this.delimiters = delimiters; |
| currentPos = nextPos = peekPos = 0; |
| maxPos = string.length(); |
| } |
| |
| /** |
| * Constructor. Comments are ignored and not returned as tokens |
| * |
| * @param header The header that is tokenized |
| * @param delimiters The delimiters to be used |
| */ |
| public HeaderTokenizer(String header, String delimiters) { |
| this(header, delimiters, true); |
| } |
| |
| /** |
| * Constructor. The RFC822 defined delimiters - RFC822 - are |
| * used to delimit ATOMS. Also comments are skipped and not |
| * returned as tokens |
| * @param header The header that is tokenized. |
| */ |
| public HeaderTokenizer(String header) { |
| this(header, RFC822); |
| } |
| |
| /** |
| * Parses the next token from this String. <p> |
| * |
| * 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 |
| */ |
| public Token next() throws ParseException { |
| Token tk; |
| |
| currentPos = nextPos; // setup currentPos |
| tk = getNext(); |
| nextPos = peekPos = currentPos; // update currentPos and peekPos |
| return tk; |
| } |
| |
| /** |
| * Peek at the next token, without actually removing the token |
| * from the parse stream. Invoking this method multiple times |
| * will return successive tokens, until <code>next()</code> is |
| * called. <p> |
| * |
| * @return the next Token |
| * @exception ParseException if the parse fails |
| */ |
| public Token peek() throws ParseException { |
| Token tk; |
| |
| currentPos = peekPos; // setup currentPos |
| tk = getNext(); |
| peekPos = currentPos; // update peekPos |
| return tk; |
| } |
| |
| /** |
| * Return the rest of the Header. |
| * |
| * @return String rest of header. null is returned if we are |
| * already at end of header |
| */ |
| public String getRemainder() { |
| return string.substring(nextPos); |
| } |
| |
| /* |
| * Return the next token starting from 'currentPos'. After the |
| * parse, 'currentPos' is updated to point to the start of the |
| * next token. |
| */ |
| private Token getNext() throws ParseException { |
| // 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(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)); |
| } |
| |
| // Skip SPACE, HT, CR and NL |
| 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; |
| } |
| |
| /* Process escape sequences and embedded LWSPs from a comment or |
| * quoted string. |
| */ |
| private static String filterToken(String s, int start, int end) { |
| StringBuilder sb = new StringBuilder(); |
| 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(); |
| } |
| } |
