tapestry/tapestry-framework/src/java/org/apache/tapestry/json/Cookie.java

package org.apache.tapestry.json;

/*
 Copyright (c) 2002 JSON.org

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 The Software shall be used for Good, not Evil.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */

import java.text.ParseException;

/**
 * Convert a web browser cookie specification to a JSONObject and back. JSON and
 * Cookies are both notations for name/value pairs.
 * 
 * @author JSON.org
 * @version 0.1
 */
public final class Cookie
{

    /* defeat instantiation */
    private Cookie()
    {
    }

    /**
     * Produce a copy of a string in which the characters '+', '%', '=', ';' and
     * control characters are replaced with "%hh". This is a gentle form of URL
     * encoding, attempting to cause as little distortion to the string as
     * possible. The characters '=' and ';' are meta characters in cookies. By
     * convention, they are escaped using the URL-encoding. This is only a
     * convention, not a standard. Often, cookies are expected to have encoded
     * values. We encode '=' and ';' because we must. We encode '%' and '+'
     * because they are meta characters in URL encoding.
     * 
     * @param string
     *            The source string.
     * @return The escaped result.
     */
    public static String escape(String string)
    {
        char c;
        String s = string.trim();
        StringBuffer sb = new StringBuffer();
        int len = s.length();
        for(int i = 0; i < len; i += 1)
        {
            c = s.charAt(i);
            if (c < ' ' || c == '+' || c == '%' || c == '=' || c == ';')
            {
                sb.append('%');
                sb.append(Character.forDigit((char) ((c >>> 4) & 0x0f), 16));
                sb.append(Character.forDigit((char) (c & 0x0f), 16));
            }
            else
            {
                sb.append(c);
            }
        }
        return sb.toString();
    }

    /**
     * Convert a cookie specification string into a JSONObject. The string will
     * contain a name value pair separated by '='. The name and the value will
     * be unescaped, possibly converting '+' and '%' sequences. The cookie
     * properties may follow, separated by ';', also represented as name=value
     * (except the secure property, which does not have a value). The name will
     * be stored under the key "name", and the value will be stored under the
     * key "value". This method does not do checking or validation of the
     * parameters. It only converts the cookie string into a JSONObject.
     * 
     * @param string
     *            The cookie specification string.
     * @return A JSONObject containing "name", "value", and possibly other
     *         members.
     * @throws ParseException
     */
    public static JSONObject toJSONObject(String string)
        throws ParseException
    {
        String n;
        JSONObject o = new JSONObject();
        Object v;
        JSONTokener x = new JSONTokener(string);
        o.put("name", x.nextTo('='));
        x.next('=');
        o.put("value", x.nextTo(';'));
        x.next();
        while(x.more())
        {
            n = JSONTokener.unescape(x.nextTo("=;"));
            if (x.next() != '=')
            {
                if (n.equals("secure"))
                {
                    v = Boolean.TRUE;
                }
                else
                {
                    throw x.syntaxError("Missing '=' in cookie parameter.");
                }
            }
            else
            {
                v = JSONTokener.unescape(x.nextTo(';'));
                x.next();
            }
            o.put(n, v);
        }
        return o;
    }

    /**
     * Convert a JSONObject into a cookie specification string. The JSONObject
     * must contain "name" and "value" members. If the JSONObject contains
     * "expires", "domain", "path", or "secure" members, they will be appended
     * to the cookie specification string. All other members are ignored.
     * 
     * @param o
     *            A JSONObject
     * @return A cookie specification string
     */
    public static String toString(JSONObject o)
    {
        StringBuffer sb = new StringBuffer();

        sb.append(escape(o.getString("name")));
        sb.append("=");
        sb.append(escape(o.getString("value")));
        if (o.has("expires"))
        {
            sb.append(";expires=");
            sb.append(o.getString("expires"));
        }
        if (o.has("domain"))
        {
            sb.append(";domain=");
            sb.append(escape(o.getString("domain")));
        }
        if (o.has("path"))
        {
            sb.append(";path=");
            sb.append(escape(o.getString("path")));
        }
        if (o.optBoolean("secure"))
        {
            sb.append(";secure");
        }
        return sb.toString();
    }
}