CookieManager provides a concrete implementation of CookieHandler, which separates the storage of cookies from the policy surrounding accepting and rejecting cookies. A CookieManager is initialized with a CookieStore which manages storage, and a CookiePolicy object, which makes policy decisions on cookie acceptance/rejection.

The HTTP cookie management in java.net package looks like:

use
 CookieHandler <------- HttpURLConnection
       ^
       | impl
       |         use
 CookieManager -------> CookiePolicy
             |   use
             |--------> HttpCookie
             |              ^
             |              | use
             |   use        |
             |--------> CookieStore
                            ^
                            | impl
                            |
                  Internal in-memory implementation

• CookieHandler is at the core of cookie management. User can call CookieHandler.setDefault to set a concrete CookieHanlder implementation to be used.
• CookiePolicy.shouldAccept will be called by CookieManager.put to see whether or not one cookie should be accepted and put into cookie store. User can use any of three pre-defined CookiePolicy, namely ACCEPT_ALL, ACCEPT_NONE and ACCEPT_ORIGINAL_SERVER, or user can define his own CookiePolicy implementation and tell CookieManager to use it.
• CookieStore is the place where any accepted HTTP cookie is stored in. If not specified when created, a CookieManager instance will use an internal in-memory implementation. Or user can implements one and tell CookieManager to use it.
• Currently, only CookieStore.add(URI, HttpCookie) and CookieStore.get(URI) are used by CookieManager. Others are for completeness and might be needed by a more sophisticated CookieStore implementation, e.g. a NetscapeCookieSotre.

There're various ways user can hook up his own HTTP cookie management behavior, e.g.

• Use CookieHandler.setDefault to set a brand new CookieHandler implementation
• Let CookieManager be the default CookieHandler implementation, but implement user's own CookieStore and CookiePolicy and tell default CookieManager to use them:

  // this should be done at the beginning of an HTTP session
  CookieHandler.setDefault(new CookieManager(new MyCookieStore(), new MyCookiePolicy()));

• Let CookieManager be the default CookieHandler implementation, but use customized CookiePolicy:

  // this should be done at the beginning of an HTTP session
  CookieHandler.setDefault(new CookieManager());
  // this can be done at any point of an HTTP session
  ((CookieManager)CookieHandler.getDefault()).setCookiePolicy(new MyCookiePolicy());

The implementation conforms to RFC 2965, section 3.3.

Create a new cookie manager.

This constructor will create new cookie manager with default cookie store and accept policy. The effect is same as CookieManager(null, null).

To set the cookie policy of this cookie manager.

A instance of CookieManager will have cookie policy ACCEPT_ORIGINAL_SERVER by default. Users always can call this method to set another cookie policy.

Gets all the applicable cookies from a cookie cache for the specified uri in the request header.

The URI passed as an argument specifies the intended use for the cookies. In particular the scheme should reflect whether the cookies will be sent over http, https or used in another context like javascript. The host part should reflect either the destination of the cookies or their origin in the case of javascript.

It is up to the implementation to take into account the URI and the cookies attributes and security settings to determine which ones should be returned.

HTTP protocol implementers should make sure that this method is called after all request headers related to choosing cookies are added, and before the request is sent.