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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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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.
 * 
 * 

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. * *

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. * *

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. * *

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. * *

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. * * * @author Various * @version $Version$ * */ // 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. * *

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. * *

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 * setValue method. * *

By default, cookies are created according to the Netscape * cookie specification. The version can be changed with the * setVersion method. * * * @param name a String specifying the name of the cookie * * @param value a String 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 String 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 * null if the cookie has no comment. * * @return a String containing the comment, * or null if none * * @see #setComment * */ public String getComment() { return comment; } /** * * Specifies the domain within which this cookie should be presented. * *

The form of the domain name is specified by RFC 2109. A domain * name begins with a dot (.foo.com) and means that * the cookie is visible to servers in a specified Domain Name System * (DNS) zone (for example, www.foo.com, but not * a.b.foo.com). By default, cookies are only returned * to the server that sent them. * * * @param pattern a String 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 String containing the domain name * * @see #setDomain * */ public String getDomain() { return domain; } /** * Sets the maximum age of the cookie in seconds. * *

A positive value indicates that the cookie will expire * after that many seconds have passed. Note that the value is * the maximum age when the cookie will expire, not the cookie's * current age. * *

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, -1 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. * *

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, /catalog, which makes the cookie * visible to all directories on the server under /catalog. * *

Consult RFC 2109 (available on the Internet) for more * information on setting path names for cookies. * * * @param uri a String 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 String specifying a path that contains * a servlet name, for example, /catalog * * @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. * *

The default value is false. * * @param flag if true, sends the cookie from the browser * to the server only when using a secure protocol; * if false, sent on any protocol * * @see #getSecure * */ public void setSecure(boolean flag) { secure = flag; } /** * Returns true if the browser is sending cookies * only over a secure protocol, or false if the * browser can send cookies using any protocol. * * @return true if the browser uses a secure protocol; * otherwise, true * * @see #setSecure * */ public boolean getSecure() { return secure; } /** * Returns the name of the cookie. The name cannot be changed after * creation. * * @return a String 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. * *

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 String specifying the new value * * * @see #getValue * @see Cookie * */ public void setValue(String newValue) { value = newValue; } /** * Returns the value of the cookie. * * @return a String 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. * *

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 String to be tested * * @return true if the String is * a reserved token; false * 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 java.lang.Object.clone * method to return a copy of this cookie. * * */ public Object clone() { try { return super.clone(); } catch (CloneNotSupportedException e) { throw new RuntimeException(e.getMessage()); } } }





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