001    package org.apache.tapestry.json;
002    
003    /*
004     Copyright (c) 2002 JSON.org
005    
006     Permission is hereby granted, free of charge, to any person obtaining a copy
007     of this software and associated documentation files (the "Software"), to deal
008     in the Software without restriction, including without limitation the rights
009     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
010     copies of the Software, and to permit persons to whom the Software is
011     furnished to do so, subject to the following conditions:
012    
013     The above copyright notice and this permission notice shall be included in all
014     copies or substantial portions of the Software.
015    
016     The Software shall be used for Good, not Evil.
017    
018     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
019     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
020     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
021     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
022     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
023     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
024     SOFTWARE.
025     */
026    
027    import java.text.ParseException;
028    
029    /**
030     * Convert a web browser cookie specification to a JSONObject and back. JSON and
031     * Cookies are both notations for name/value pairs.
032     * 
033     * @author JSON.org
034     * @version 0.1
035     */
036    public final class Cookie
037    {
038    
039        /* defeat instantiation */
040        private Cookie()
041        {
042        }
043    
044        /**
045         * Produce a copy of a string in which the characters '+', '%', '=', ';' and
046         * control characters are replaced with "%hh". This is a gentle form of URL
047         * encoding, attempting to cause as little distortion to the string as
048         * possible. The characters '=' and ';' are meta characters in cookies. By
049         * convention, they are escaped using the URL-encoding. This is only a
050         * convention, not a standard. Often, cookies are expected to have encoded
051         * values. We encode '=' and ';' because we must. We encode '%' and '+'
052         * because they are meta characters in URL encoding.
053         * 
054         * @param string
055         *            The source string.
056         * @return The escaped result.
057         */
058        public static String escape(String string)
059        {
060            char c;
061            String s = string.trim();
062            StringBuffer sb = new StringBuffer();
063            int len = s.length();
064            for(int i = 0; i < len; i += 1)
065            {
066                c = s.charAt(i);
067                if (c < ' ' || c == '+' || c == '%' || c == '=' || c == ';')
068                {
069                    sb.append('%');
070                    sb.append(Character.forDigit((char) ((c >>> 4) & 0x0f), 16));
071                    sb.append(Character.forDigit((char) (c & 0x0f), 16));
072                }
073                else
074                {
075                    sb.append(c);
076                }
077            }
078            return sb.toString();
079        }
080    
081        /**
082         * Convert a cookie specification string into a JSONObject. The string will
083         * contain a name value pair separated by '='. The name and the value will
084         * be unescaped, possibly converting '+' and '%' sequences. The cookie
085         * properties may follow, separated by ';', also represented as name=value
086         * (except the secure property, which does not have a value). The name will
087         * be stored under the key "name", and the value will be stored under the
088         * key "value". This method does not do checking or validation of the
089         * parameters. It only converts the cookie string into a JSONObject.
090         * 
091         * @param string
092         *            The cookie specification string.
093         * @return A JSONObject containing "name", "value", and possibly other
094         *         members.
095         * @throws ParseException
096         */
097        public static JSONObject toJSONObject(String string)
098            throws ParseException
099        {
100            String n;
101            JSONObject o = new JSONObject();
102            Object v;
103            JSONTokener x = new JSONTokener(string);
104            o.put("name", x.nextTo('='));
105            x.next('=');
106            o.put("value", x.nextTo(';'));
107            x.next();
108            while(x.more())
109            {
110                n = JSONTokener.unescape(x.nextTo("=;"));
111                if (x.next() != '=')
112                {
113                    if (n.equals("secure"))
114                    {
115                        v = Boolean.TRUE;
116                    }
117                    else
118                    {
119                        throw x.syntaxError("Missing '=' in cookie parameter.");
120                    }
121                }
122                else
123                {
124                    v = JSONTokener.unescape(x.nextTo(';'));
125                    x.next();
126                }
127                o.put(n, v);
128            }
129            return o;
130        }
131    
132        /**
133         * Convert a JSONObject into a cookie specification string. The JSONObject
134         * must contain "name" and "value" members. If the JSONObject contains
135         * "expires", "domain", "path", or "secure" members, they will be appended
136         * to the cookie specification string. All other members are ignored.
137         * 
138         * @param o
139         *            A JSONObject
140         * @return A cookie specification string
141         */
142        public static String toString(JSONObject o)
143        {
144            StringBuffer sb = new StringBuffer();
145    
146            sb.append(escape(o.getString("name")));
147            sb.append("=");
148            sb.append(escape(o.getString("value")));
149            if (o.has("expires"))
150            {
151                sb.append(";expires=");
152                sb.append(o.getString("expires"));
153            }
154            if (o.has("domain"))
155            {
156                sb.append(";domain=");
157                sb.append(escape(o.getString("domain")));
158            }
159            if (o.has("path"))
160            {
161                sb.append(";path=");
162                sb.append(escape(o.getString("path")));
163            }
164            if (o.optBoolean("secure"))
165            {
166                sb.append(";secure");
167            }
168            return sb.toString();
169        }
170    }