1 /*
2 * $Source$
3 * $Revision$
4 *
5 * Copyright (C) 2001 William Chesters
6 *
7 * Part of Melati (http://melati.org), a framework for the rapid
8 * development of clean, maintainable web applications.
9 *
10 * Melati is free software; Permission is granted to copy, distribute
11 * and/or modify this software under the terms either:
12 *
13 * a) the GNU General Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at your option)
15 * any later version,
16 *
17 * or
18 *
19 * b) any version of the Melati Software License, as published
20 * at http://melati.org
21 *
22 * You should have received a copy of the GNU General Public License and
23 * the Melati Software License along with this program;
24 * if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26 * GNU General Public License and visit http://melati.org to obtain the
27 * Melati Software License.
28 *
29 * Feel free to contact the Developers of Melati (http://melati.org),
30 * if you would like to work out a different arrangement than the options
31 * outlined here. It is our intention to allow Melati to be used by as
32 * wide an audience as possible.
33 *
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
38 *
39 * Contact details for copyright holder:
40 *
41 * William Chesters <williamc At paneris.org>
42 */
43 package org.melati.util;
44
45 import java.util.Enumeration;
46 import java.util.NoSuchElementException;
47
48 /**
49 * A utility for tokenising a string made up of comma-separated
50 * variables. Unlike Tim's effort, it handles quoted variables as
51 * well.
52 *
53 * <PRE>
54 * foo, bar om,,"baz, ,oof",xyz, -<
55 * "foo", " bar om", "", "baz, , oof", "xyz", ""
56 * </PRE>
57 *
58 * @author williamc AT paneris.org
59 */
60
61 public class CSVStringEnumeration implements Enumeration<String> {
62
63 private String line = "";
64 private boolean emptyLastField = false;
65 int p = 0;
66
67 /**
68 * Look at a new string.
69 */
70 public void reset(String lineP) {
71 this.line = lineP;
72 p = 0;
73 }
74
75 /**
76 * Are there any more tokens to come?
77 * {@inheritDoc}
78 * @see java.util.Enumeration#hasMoreElements()
79 */
80 public boolean hasMoreElements() {
81 return emptyLastField || p < line.length();
82 }
83
84 /**
85 * Return the next token as an <TT>Object</TT>.
86 * {@inheritDoc}
87 * @see java.util.Enumeration#nextElement()
88 */
89 public final String nextElement() {
90 return nextToken();
91 }
92
93 /**
94 * @return the next token as a <TT>String</TT>.
95 */
96 public String nextToken() {
97
98 if (emptyLastField) {
99 emptyLastField = false;
100 return "";
101 }
102
103 if (p >= line.length()) throw new NoSuchElementException();
104
105 if (line.charAt(p) == '"') {
106 ++p;
107 // we need to allow for quotes inside quoted fields, so now test for ",
108 int q = line.indexOf("\",", p);
109 // if it is not there, we are (hopefully) at the end of a line
110 if (q == -1 && (line.indexOf('"', p) == line.length()-1))
111 q = line.length()-1;
112
113 if (q == -1) {
114 p = line.length();
115 throw new IllegalArgumentException("Unclosed quotes");
116 }
117
118 String it = line.substring(p, q);
119
120 ++q;
121 p = q+1;
122 if (q < line.length()) {
123 if (line.charAt(q) != ',') {
124 p = line.length();
125 throw new IllegalArgumentException("No comma after quotes");
126 }
127 else if (q == line.length() - 1)
128 emptyLastField = true;
129 }
130 return it;
131 } else {
132 int q = line.indexOf(',', p);
133 if (q == -1) {
134 String it = line.substring(p);
135 p = line.length();
136 return it;
137 } else {
138 String it = line.substring(p, q);
139 if (q == line.length() - 1)
140 emptyLastField = true;
141 p = q + 1;
142 return it;
143 }
144 }
145 }
146
147 }