/**
    *
    * Copyright 2003-2004 The Apache Software Foundation
    *
    *  Licensed under the Apache License, Version 2.0 (the "License");
    *  you may not use this file except in compliance with the License.
    *  You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  
  //
  // This source code implements specifications defined by the Java
  // Community Process. In order to remain compliant with the specification
  // DO NOT add / change / or delete method signatures!
  //
  
  package javax.servlet.http;
  
  import java.text.MessageFormat;
  import java.util.ResourceBundle;
  
  /**
   * Creates a cookie, a small amount of information sent by a servlet to
   * a Web browser, saved by the browser, and later sent back to the server.
   * A cookie's value can uniquely
   * identify a client, so cookies are commonly used for session management.
   *
   * <p>A cookie has a name, a single value, and optional attributes
   * such as a comment, path and domain qualifiers, a maximum age, and a
   * version number. Some Web browsers have bugs in how they handle the
   * optional attributes, so use them sparingly to improve the interoperability
   * of your servlets.
   *
   * <p>The servlet sends cookies to the browser by using the
   * {@link HttpServletResponse#addCookie} method, which adds
   * fields to HTTP response headers to send cookies to the
   * browser, one at a time. The browser is expected to
   * support 20 cookies for each Web server, 300 cookies total, and
   * may limit cookie size to 4 KB each.
   *
   * <p>The browser returns cookies to the servlet by adding
   * fields to HTTP request headers. Cookies can be retrieved
   * from a request by using the {@link HttpServletRequest#getCookies} method.
   * Several cookies might have the same name but different path attributes.
   *
   * <p>Cookies affect the caching of the Web pages that use them.
   * HTTP 1.0 does not cache pages that use cookies created with
   * this class. This class does not support the cache control
   * defined with HTTP 1.1.
   *
   * <p>This class supports both the Version 0 (by Netscape) and Version 1
   * (by RFC 2109) cookie specifications. By default, cookies are
   * created using Version 0 to ensure the best interoperability.
   *
   * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
   */
  
  // XXX would implement java.io.Serializable too, but can't do that
  // so long as sun.servlet.* must run on older JDK 1.02 JVMs which
  // don't include that support.
  
  public class Cookie implements Cloneable {
      private static final String LSTRING_FILE = "javax.servlet.http.LocalStrings";
      private static ResourceBundle lStrings = ResourceBundle.getBundle(LSTRING_FILE);
  
      //
      // The value of the cookie itself.
      //
  
      private String name; // NAME= ... "$Name" style is reserved
      private String value; // value of NAME
  
      //
      // Attributes encoded in the header's cookie fields.
      //
  
      private String comment; // ;Comment=VALUE ... describes cookie's use
      // ;Discard ... implied by maxAge < 0
      private String domain; // ;Domain=VALUE ... domain that sees cookie
      private int maxAge = -1; // ;Max-Age=VALUE ... cookies auto-expire
      private String path; // ;Path=VALUE ... URLs that see the cookie
      private boolean secure; // ;Secure ... e.g. use SSL
      private int version = 0; // ;Version=1 ... means RFC 2109++ style
  
  
      /**
       * Constructs a cookie with a specified name and value.
       *
       * <p>The name must conform to RFC 2109. That means it can contain
       * only ASCII alphanumeric characters and cannot contain commas,
       * semicolons, or white space or begin with a $ character. The cookie's
       * name cannot be changed after creation.
      *
      * <p>The value can be anything the server chooses to send. Its
      * value is probably of interest only to the server. The cookie's
      * value can be changed after creation with the
      * <code>setValue</code> method.
      *
      * <p>By default, cookies are created according to the Netscape
      * cookie specification. The version can be changed with the
      * <code>setVersion</code> method.
      *
      *
      * @param name a <code>String</code> specifying the name of the cookie
      *
      * @param value a <code>String</code> specifying the value of the cookie
      *
      * @throws IllegalArgumentException if the cookie name contains illegal characters
      * (for example, a comma, space, or semicolon) or it is one of the tokens reserved for use
      * by the cookie protocol
      *
      * @see #setValue
      * @see #setVersion
      */
     public Cookie(String name, String value) {
         if (!isToken(name)
                 || name.equalsIgnoreCase("Comment") // rfc2019
                 || name.equalsIgnoreCase("Discard") // 2019++
                 || name.equalsIgnoreCase("Domain")
                 || name.equalsIgnoreCase("Expires") // (old cookies)
                 || name.equalsIgnoreCase("Max-Age") // rfc2019
                 || name.equalsIgnoreCase("Path")
                 || name.equalsIgnoreCase("Secure")
                 || name.equalsIgnoreCase("Version")
                 || name.startsWith("$")
         ) {
             String errMsg = lStrings.getString("err.cookie_name_is_token");
             Object[] errArgs = new Object[1];
             errArgs[0] = name;
             errMsg = MessageFormat.format(errMsg, errArgs);
             throw new IllegalArgumentException(errMsg);
         }
 
         this.name = name;
         this.value = value;
     }
 
     /**
      * Specifies a comment that describes a cookie's purpose.
      * The comment is useful if the browser presents the cookie
      * to the user. Comments
      * are not supported by Netscape Version 0 cookies.
      *
      * @param purpose a <code>String</code> specifying the comment
      * to display to the user
      *
      * @see #getComment
      */
     public void setComment(String purpose) {
         comment = purpose;
     }
 
     /**
      * Returns the comment describing the purpose of this cookie, or
      * <code>null</code> if the cookie has no comment.
      *
      * @return a <code>String</code> containing the comment,
      * or <code>null</code> if none
      *
      * @see #setComment
      */
     public String getComment() {
         return comment;
     }
 
     /**
      * Specifies the domain within which this cookie should be presented.
      *
      * <p>The form of the domain name is specified by RFC 2109. A domain
      * name begins with a dot (<code>.foo.com</code>) and means that
      * the cookie is visible to servers in a specified Domain Name System
      * (DNS) zone (for example, <code>www.foo.com</code>, but not
      * <code>a.b.foo.com</code>). By default, cookies are only returned
      * to the server that sent them.
      *
      * @param pattern a <code>String</code> containing the domain name
      * within which this cookie is visible; form is according to RFC 2109
      *
      * @see #getDomain
      */
     public void setDomain(String pattern) {
         domain = pattern.toLowerCase(); // IE allegedly needs this
     }
 
     /**
      * Returns the domain name set for this cookie. The form of
      * the domain name is set by RFC 2109.
      *
      * @return a <code>String</code> containing the domain name
      *
      * @see #setDomain
      */
     public String getDomain() {
         return domain;
     }
 
     /**
      * Sets the maximum age of the cookie in seconds.
      *
      * <p>A positive value indicates that the cookie will expire
      * after that many seconds have passed. Note that the value is
      * the <i>maximum</i> age when the cookie will expire, not the cookie's
      * current age.
      *
      * <p>A negative value means
      * that the cookie is not stored persistently and will be deleted
      * when the Web browser exits. A zero value causes the cookie
      * to be deleted.
      *
      * @param expiry an integer specifying the maximum age of the
      * cookie in seconds; if negative, means the cookie is not stored;
      * if zero, deletes the cookie
      *
      * @see #getMaxAge
      */
     public void setMaxAge(int expiry) {
         maxAge = expiry;
     }
 
     /**
      * Returns the maximum age of the cookie, specified in seconds,
      * By default, <code>-1</code> indicating the cookie will persist
      * until browser shutdown.
      *
      * @return an integer specifying the maximum age of the
      * cookie in seconds; if negative, means the cookie persists
      * until browser shutdown
      *
      * @see #setMaxAge
      */
     public int getMaxAge() {
         return maxAge;
     }
 
     /**
      * Specifies a path for the cookie
      * to which the client should return the cookie.
      *
      * <p>The cookie is visible to all the pages in the directory
      * you specify, and all the pages in that directory's subdirectories.
      * A cookie's path must include the servlet that set the cookie,
      * for example, <i>/catalog</i>, which makes the cookie
      * visible to all directories on the server under <i>/catalog</i>.
      *
      * <p>Consult RFC 2109 (available on the Internet) for more
      * information on setting path names for cookies.
      *
      * @param uri a <code>String</code> specifying a path
      *
      * @see #getPath
      */
     public void setPath(String uri) {
         path = uri;
     }
 
     /**
      * Returns the path on the server
      * to which the browser returns this cookie. The
      * cookie is visible to all subpaths on the server.
      *
      * @return a <code>String</code> specifying a path that contains
      * a servlet name, for example, <i>/catalog</i>
      *
      * @see #setPath
      */
     public String getPath() {
         return path;
     }
 
     /**
      * Indicates to the browser whether the cookie should only be sent
      * using a secure protocol, such as HTTPS or SSL.
      *
      * <p>The default value is <code>false</code>.
      *
      * @param flag if <code>true</code>, sends the cookie from the browser
      * to the server only when using a secure protocol; if <code>false</code>,
      * sent on any protocol
      *
      * @see #getSecure
      */
     public void setSecure(boolean flag) {
         secure = flag;
     }
 
     /**
      * Returns <code>true</code> if the browser is sending cookies
      * only over a secure protocol, or <code>false</code> if the
      * browser can send cookies using any protocol.
      *
      * @return <code>true</code> if the browser uses a secure protocol;
      * otherwise, <code>true</code>
      *
      * @see #setSecure
      */
     public boolean getSecure() {
         return secure;
     }
 
     /**
      * Returns the name of the cookie. The name cannot be changed after
      * creation.
      *
      * @return a <code>String</code> specifying the cookie's name
      */
     public String getName() {
         return name;
     }
 
     /**
      * Assigns a new value to a cookie after the cookie is created.
      * If you use a binary value, you may want to use BASE64 encoding.
      *
      * <p>With Version 0 cookies, values should not contain white
      * space, brackets, parentheses, equals signs, commas,
      * double quotes, slashes, question marks, at signs, colons,
      * and semicolons. Empty values may not behave the same way
      * on all browsers.
      *
      * @param newValue a <code>String</code> specifying the new value
      *
      * @see #getValue
      * @see Cookie
      */
     public void setValue(String newValue) {
         value = newValue;
     }
 
     /**
      * Returns the value of the cookie.
      *
      * @return a <code>String</code> containing the cookie's
      * present value
      *
      * @see #setValue
      * @see Cookie
      */
     public String getValue() {
         return value;
     }
 
     /**
      * Returns the version of the protocol this cookie complies
      * with. Version 1 complies with RFC 2109,
      * and version 0 complies with the original
      * cookie specification drafted by Netscape. Cookies provided
      * by a browser use and identify the browser's cookie version.
      *
      * @return 0 if the cookie complies with the original Netscape
      * specification; 1 if the cookie complies with RFC 2109
      *
      * @see #setVersion
      */
     public int getVersion() {
         return version;
     }
 
     /**
      * Sets the version of the cookie protocol this cookie complies
      * with. Version 0 complies with the original Netscape cookie
      * specification. Version 1 complies with RFC 2109.
      *
      * <p>Since RFC 2109 is still somewhat new, consider
      * version 1 as experimental; do not use it yet on production sites.
      *
      * @param v 0 if the cookie should comply with the original Netscape
      * specification; 1 if the cookie should comply with RFC 2109
      *
      * @see #getVersion
      */
     public void setVersion(int v) {
         version = v;
     }
 
     // Note -- disabled for now to allow full Netscape compatibility
     // from RFC 2068, token special case characters
     //
     // private static final String tspecials = "()<>@,;:\\\"/[]?={} \t";
 
     private static final String tspecials = ",; ";
 
     /**
      * Tests a string and returns true if the string counts as a
      * reserved token in the Java language.
      *
      * @param value the <code>String</code> to be tested
      *
      * @return <code>true</code> if the <code>String</code> is
      * a reserved token; <code>false</code> if it is not
      */
     private boolean isToken(String value) {
         int len = value.length();
 
         for (int i = 0; i < len; i++) {
             char c = value.charAt(i);
 
             if (c < 0x20 || c >= 0x7f || tspecials.indexOf(c) != -1)
                 return false;
         }
         return true;
     }
 
     /**
      * Overrides the standard <code>java.lang.Object.clone</code>
      * method to return a copy of this cookie.
      */
     public Object clone() {
         try {
             return super.clone();
         } catch (CloneNotSupportedException e) {
             throw new RuntimeException(e.getMessage());
         }
     }
 }