Source code: javax/mail/internet/HeaderTokenizer.java
1 /**
2 *
3 * Copyright 2003-2004 The Apache Software Foundation
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package javax.mail.internet;
19
20 /**
21 * @version $Rev: 54266 $ $Date: 2004-10-10 14:02:50 -0700 (Sun, 10 Oct 2004) $
22 */
23 public class HeaderTokenizer {
24 public static class Token {
25 // Constant values from J2SE 1.4 API Docs (Constant values)
26 public static final int ATOM = -1;
27 public static final int COMMENT = -3;
28 public static final int EOF = -4;
29 public static final int QUOTEDSTRING = -2;
30 private int _type;
31 private String _value;
32
33 public Token(int type, String value) {
34 _type = type;
35 _value = value;
36 }
37
38 public int getType() {
39 return _type;
40 }
41
42 public String getValue() {
43 return _value;
44 }
45 }
46
47 private static final Token EOF = new Token(Token.EOF, null);
48 // characters not allowed in MIME
49 public static final String MIME = "()<>@,;:\\\"\t []/?=";
50 // charaters not allowed in RFC822
51 public static final String RFC822 = "()<>@,;:\\\"\t .[]";
52 private static final String WHITE = " \t\n\r";
53 private String _delimiters;
54 private String _header;
55 private boolean _skip;
56 private int pos;
57
58 public HeaderTokenizer(String header) {
59 this(header, RFC822);
60 }
61
62 public HeaderTokenizer(String header, String delimiters) {
63 this(header, delimiters, true);
64 }
65
66 public HeaderTokenizer(String header,
67 String delimiters,
68 boolean skipComments) {
69 _skip = skipComments;
70 _header = header;
71 _delimiters = delimiters;
72 }
73
74 public String getRemainder() {
75 return _header.substring(pos);
76 }
77
78 public Token next() throws ParseException {
79 return readToken();
80 }
81
82 public Token peek() throws ParseException {
83 int start = pos;
84 try {
85 return readToken();
86 } finally {
87 pos = start;
88 }
89 }
90
91 /**
92 * @return
93 */
94 private Token readAtomicToken() {
95 // skip to next delimiter
96 int start = pos;
97 while (++pos < _header.length()
98 && _delimiters.indexOf(_header.charAt(pos)) == -1)
99 ;
100 return new Token(Token.ATOM, _header.substring(start, pos));
101 }
102
103 private Token readToken() throws ParseException {
104 if (pos >= _header.length()) {
105 return EOF;
106 } else {
107 char c = _header.charAt(pos);
108 if (c == '(') {
109 Token comment = readUntil(')', Token.COMMENT);
110 if (_skip) {
111 return readToken();
112 } else {
113 return comment;
114 }
115 } else if (c == '\"') {
116 return readUntil('\"', Token.QUOTEDSTRING);
117 } else if (WHITE.indexOf(c) != -1) {
118 eatWhiteSpace();
119 return readToken();
120 } else if (_delimiters.indexOf(c) != -1) {
121 pos++;
122 return new Token(Token.ATOM, String.valueOf(c));
123 } else {
124 return readAtomicToken();
125 }
126 }
127 }
128
129 /**
130 * @return
131 */
132 private Token readUntil(char end, int type) {
133 int start = ++pos;
134 // skip to end of comment/string
135 while (++pos < _header.length()
136 && _header.charAt(pos) != end)
137 ;
138 String value = _header.substring(start, pos++);
139 return new Token(type, value);
140 }
141
142 /**
143 * @return
144 */
145 private void eatWhiteSpace() {
146 // skip to end of whitespace
147 while (++pos < _header.length()
148 && WHITE.indexOf(_header.charAt(pos)) != -1)
149 ;
150 }
151 }