Class Cookie

java.lang.Object
jakarta.servlet.http.Cookie
All Implemented Interfaces:
Serializable, Cloneable
public class Cookie extends Object implements Cloneable, Serializable
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 HttpServletResponse.addCookie(jakarta.servlet.http.Cookie) method, which adds fields to HTTP response headers to send cookies to the browser, one at a time. The browser is expected to support 50 cookies for each domain, 3000 cookies total, and may limit cookie size to 4 KiB 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 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 the RFC 6265 specification.

See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Cookie(String name, String value)
    Constructs a cookie with a specified name and value.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    clone()
    Overrides the standard java.lang.Object.clone method to return a copy of this cookie.
    boolean
    equals(Object obj)
     
    String
    getAttribute(String name)
    Obtain the value for a given attribute.
    Map<String,String>
    getAttributes()
    Obtain the Map of attributes and values (excluding version) for this cookie.
    String
    getComment()
    Deprecated, for removal: This API element is subject to removal in a future version.
    This is no longer required with RFC 6265
    String
    getDomain()
    Returns the domain name set for this cookie.
    int
    getMaxAge()
    Returns the maximum age of the cookie, specified in seconds, By default, -1 indicating the cookie will persist until browser shutdown.
    String
    getName()
    Returns the name of the cookie.
    String
    getPath()
    Returns the path on the server to which the browser returns this cookie.
    boolean
    getSecure()
    Returns true if the browser is sending cookies only over a secure protocol, or false if the browser can send cookies using any protocol.
    String
    getValue()
    Returns the value of the cookie.
    int
    getVersion()
    Deprecated, for removal: This API element is subject to removal in a future version.
    This is no longer required with RFC 6265
    int
    hashCode()
     
    boolean
    isHttpOnly()
    Gets the flag that controls if this cookie will be hidden from scripts on the client side.
    void
    setAttribute(String name, String value)
    Sets the value for the given cookie attribute.
    void
    setComment(String purpose)
    Deprecated, for removal: This API element is subject to removal in a future version.
    This is no longer required with RFC 6265
    void
    setDomain(String pattern)
    Specifies the domain within which this cookie should be presented.
    void
    setHttpOnly(boolean httpOnly)
    Sets the flag that controls if this cookie will be hidden from scripts on the client side.
    void
    setMaxAge(int expiry)
    Sets the maximum age of the cookie in seconds.
    void
    setPath(String uri)
    Specifies a path for the cookie to which the client should return the cookie.
    void
    setSecure(boolean flag)
    Indicates to the browser whether the cookie should only be sent using a secure protocol, such as HTTPS or SSL.
    void
    setValue(String newValue)
    Assigns a new value to a cookie after the cookie is created.
    void
    setVersion(int v)
    Deprecated, for removal: This API element is subject to removal in a future version.
    This is no longer required with RFC 6265

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Cookie

      public Cookie(String name, String value)
      Constructs a cookie with a specified name and value.

      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.

      Parameters:
      name - a String specifying the name of the cookie
      value - a String specifying the value of the cookie
      Throws:
      IllegalArgumentException - if the cookie name contains illegal characters
      See Also:

  • Method Details

    • setComment

      @Deprecated(since="Servlet 6.0", forRemoval=true) public void setComment(String purpose)
      Deprecated, for removal: This API element is subject to removal in a future version.
      This is no longer required with RFC 6265
      If called, this method has no effect.
      Parameters:
      purpose - ignored
      See Also:

    • getComment

      @Deprecated(since="Servlet 6.0", forRemoval=true) public String getComment()
      Deprecated, for removal: This API element is subject to removal in a future version.
      This is no longer required with RFC 6265
      With the adoption of support for RFC 6265, this method should no longer be used.
      Returns:
      always null
      See Also:

    • setDomain

      public void setDomain(String pattern)
      Specifies the domain within which this cookie should be presented.

      By default, cookies are only returned to the server that sent them.

      Parameters:
      pattern - a String containing the domain name within which this cookie is visible
      See Also:

    • getDomain

      public String getDomain()
      Returns the domain name set for this cookie.
      Returns:
      a String containing the domain name
      See Also:

    • setMaxAge

      public void setMaxAge(int expiry)
      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.

      Parameters:
      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 Also:

    • getMaxAge

      public int getMaxAge()
      Returns the maximum age of the cookie, specified in seconds, By default, -1 indicating the cookie will persist until browser shutdown.
      Returns:
      an integer specifying the maximum age of the cookie in seconds; if negative, means the cookie persists until browser shutdown
      See Also:

    • setPath

      public void setPath(String uri)
      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.

      Parameters:
      uri - a String specifying a path
      See Also:

    • getPath

      public String getPath()
      Returns the path on the server to which the browser returns this cookie. The cookie is visible to all subpaths on the server.
      Returns:
      a String specifying a path that contains a servlet name, for example, /catalog
      See Also:

    • setSecure

      public void setSecure(boolean flag)
      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.

      Parameters:
      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 Also:

    • getSecure

      public boolean getSecure()
      Returns true if the browser is sending cookies only over a secure protocol, or false if the browser can send cookies using any protocol.
      Returns:
      true if the browser uses a secure protocol; otherwise, false
      See Also:

    • getName

      public String getName()
      Returns the name of the cookie. The name cannot be changed after creation.
      Returns:
      a String specifying the cookie's name

    • setValue

      public void setValue(String newValue)
      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.

      Parameters:
      newValue - a String specifying the new value
      See Also:

    • getValue

      public String getValue()
      Returns the value of the cookie.
      Returns:
      a String containing the cookie's present value
      See Also:

    • getVersion

      @Deprecated(since="Servlet 6.0", forRemoval=true) public int getVersion()
      Deprecated, for removal: This API element is subject to removal in a future version.
      This is no longer required with RFC 6265
      With the adoption of support for RFC 6265, this method should no longer be used.
      Returns:
      Always zero
      See Also:

    • setVersion

      @Deprecated(since="Servlet 6.0", forRemoval=true) public void setVersion(int v)
      Deprecated, for removal: This API element is subject to removal in a future version.
      This is no longer required with RFC 6265
      If called, this method has no effect.
      Parameters:
      v - Ignored
      See Also:

    • clone

      public Object clone()
      Overrides the standard java.lang.Object.clone method to return a copy of this cookie.
      Overrides:
      clone in class Object

    • setHttpOnly

      public void setHttpOnly(boolean httpOnly)
      Sets the flag that controls if this cookie will be hidden from scripts on the client side.
      Parameters:
      httpOnly - The new value of the flag
      Since:
      Servlet 3.0

    • isHttpOnly

      public boolean isHttpOnly()
      Gets the flag that controls if this cookie will be hidden from scripts on the client side.
      Returns:
      true if the cookie is hidden from scripts, else false
      Since:
      Servlet 3.0

    • setAttribute

      public void setAttribute(String name, String value)
      Sets the value for the given cookie attribute. When a value is set via this method, the value returned by the attribute specific getter (if any) must be consistent with the value set via this method.
      Parameters:
      name - Name of attribute to set
      value - Value of attribute
      Throws:
      IllegalArgumentException - If the attribute name is null or contains any characters not permitted for use in Cookie names.
      NumberFormatException - If the attribute is known to be numerical but the provided value cannot be parsed to a number.
      Since:
      Servlet 6.0

    • getAttribute

      public String getAttribute(String name)
      Obtain the value for a given attribute. Values returned from this method must be consistent with the values set and returned by the attribute specific getters and setters in this class.
      Parameters:
      name - Name of attribute to return
      Returns:
      Value of specified attribute
      Since:
      Servlet 6.0

    • getAttributes

      public Map<String,String> getAttributes()
      Obtain the Map of attributes and values (excluding version) for this cookie.
      Returns:
      A read-only Map of attributes to values, excluding version.
      Since:
      Servlet 6.0

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object