1/*
2 * Copyright (c) 1996, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package sun.net.www;
27
28import java.util.Iterator;
29
30/* This is useful for the nightmare of parsing multi-part HTTP/RFC822 headers
31 * sensibly:
32 * From a String like: 'timeout=15, max=5'
33 * create an array of Strings:
34 * { {"timeout", "15"},
35 *   {"max", "5"}
36 * }
37 * From one like: 'Basic Realm="FuzzFace" Foo="Biz Bar Baz"'
38 * create one like (no quotes in literal):
39 * { {"basic", null},
40 *   {"realm", "FuzzFace"}
41 *   {"foo", "Biz Bar Baz"}
42 * }
43 * keys are converted to lower case, vals are left as is....
44 *
45 * @author Dave Brown
46 */
47
48
49public class HeaderParser {
50
51    /* table of key/val pairs */
52    String raw;
53    String[][] tab;
54    int nkeys;
55    int asize = 10; // initial size of array is 10
56
57    public HeaderParser(String raw) {
58        this.raw = raw;
59        tab = new String[asize][2];
60        parse();
61    }
62
63    private HeaderParser () {
64    }
65
66    /**
67     * create a new HeaderParser from this, whose keys (and corresponding values)
68     * range from "start" to "end-1"
69     */
70    public HeaderParser subsequence (int start, int end) {
71        if (start == 0 && end == nkeys) {
72            return this;
73        }
74        if (start < 0 || start >= end || end > nkeys)
75            throw new IllegalArgumentException ("invalid start or end");
76        HeaderParser n = new HeaderParser ();
77        n.tab = new String [asize][2];
78        n.asize = asize;
79        System.arraycopy (tab, start, n.tab, 0, (end-start));
80        n.nkeys= (end-start);
81        return n;
82    }
83
84    private void parse() {
85
86        if (raw != null) {
87            raw = raw.trim();
88            char[] ca = raw.toCharArray();
89            int beg = 0, end = 0, i = 0;
90            boolean inKey = true;
91            boolean inQuote = false;
92            int len = ca.length;
93            while (end < len) {
94                char c = ca[end];
95                if ((c == '=') && !inQuote) { // end of a key
96                    tab[i][0] = new String(ca, beg, end-beg).toLowerCase();
97                    inKey = false;
98                    end++;
99                    beg = end;
100                } else if (c == '\"') {
101                    if (inQuote) {
102                        tab[i++][1]= new String(ca, beg, end-beg);
103                        inQuote=false;
104                        do {
105                            end++;
106                        } while (end < len && (ca[end] == ' ' || ca[end] == ','));
107                        inKey=true;
108                        beg=end;
109                    } else {
110                        inQuote=true;
111                        end++;
112                        beg=end;
113                    }
114                } else if (c == ' ' || c == ',') { // end key/val, of whatever we're in
115                    if (inQuote) {
116                        end++;
117                        continue;
118                    } else if (inKey) {
119                        tab[i++][0] = (new String(ca, beg, end-beg)).toLowerCase();
120                    } else {
121                        tab[i++][1] = (new String(ca, beg, end-beg));
122                    }
123                    while (end < len && (ca[end] == ' ' || ca[end] == ',')) {
124                        end++;
125                    }
126                    inKey = true;
127                    beg = end;
128                } else {
129                    end++;
130                }
131                if (i == asize) {
132                    asize = asize * 2;
133                    String[][] ntab = new String[asize][2];
134                    System.arraycopy (tab, 0, ntab, 0, tab.length);
135                    tab = ntab;
136                }
137            }
138            // get last key/val, if any
139            if (--end > beg) {
140                if (!inKey) {
141                    if (ca[end] == '\"') {
142                        tab[i++][1] = (new String(ca, beg, end-beg));
143                    } else {
144                        tab[i++][1] = (new String(ca, beg, end-beg+1));
145                    }
146                } else {
147                    tab[i++][0] = (new String(ca, beg, end-beg+1)).toLowerCase();
148                }
149            } else if (end == beg) {
150                if (!inKey) {
151                    if (ca[end] == '\"') {
152                        tab[i++][1] = String.valueOf(ca[end-1]);
153                    } else {
154                        tab[i++][1] = String.valueOf(ca[end]);
155                    }
156                } else {
157                    tab[i++][0] = String.valueOf(ca[end]).toLowerCase();
158                }
159            }
160            nkeys=i;
161        }
162
163    }
164
165    public String findKey(int i) {
166        if (i < 0 || i > asize)
167            return null;
168        return tab[i][0];
169    }
170
171    public String findValue(int i) {
172        if (i < 0 || i > asize)
173            return null;
174        return tab[i][1];
175    }
176
177    public String findValue(String key) {
178        return findValue(key, null);
179    }
180
181    public String findValue(String k, String Default) {
182        if (k == null)
183            return Default;
184        k = k.toLowerCase();
185        for (int i = 0; i < asize; ++i) {
186            if (tab[i][0] == null) {
187                return Default;
188            } else if (k.equals(tab[i][0])) {
189                return tab[i][1];
190            }
191        }
192        return Default;
193    }
194
195    class ParserIterator implements Iterator<String> {
196        int index;
197        boolean returnsValue; // or key
198
199        ParserIterator (boolean returnValue) {
200            returnsValue = returnValue;
201        }
202        public boolean hasNext () {
203            return index<nkeys;
204        }
205        public String next () {
206            return tab[index++][returnsValue?1:0];
207        }
208        public void remove () {
209            throw new UnsupportedOperationException ("remove not supported");
210        }
211    }
212
213    public Iterator<String> keys () {
214        return new ParserIterator (false);
215    }
216
217    public Iterator<String> values () {
218        return new ParserIterator (true);
219    }
220
221    public String toString () {
222        Iterator<String> k = keys();
223        StringBuilder sb = new StringBuilder();
224        sb.append("{size=").append(asize).append(" nkeys=").append(nkeys)
225                .append(' ');
226        for (int i=0; k.hasNext(); i++) {
227            String key = k.next();
228            String val = findValue (i);
229            if (val != null && "".equals (val)) {
230                val = null;
231            }
232            sb.append(" {").append(key).append(val == null ? "" : "," + val)
233                    .append('}');
234            if (k.hasNext()) {
235                sb.append (',');
236            }
237        }
238        sb.append (" }");
239        return sb.toString();
240    }
241
242    public int findInt(String k, int Default) {
243        try {
244            return Integer.parseInt(findValue(k, String.valueOf(Default)));
245        } catch (Throwable t) {
246            return Default;
247        }
248    }
249    /*
250    public static void main(String[] a) throws Exception {
251        System.out.print("enter line to parse> ");
252        System.out.flush();
253        DataInputStream dis = new DataInputStream(System.in);
254        String line = dis.readLine();
255        HeaderParser p = new HeaderParser(line);
256        for (int i = 0; i < asize; ++i) {
257            if (p.findKey(i) == null) break;
258            String v = p.findValue(i);
259            System.out.println(i + ") " +p.findKey(i) + "="+v);
260        }
261        System.out.println("Done!");
262
263    }
264    */
265}
266