public interface PolicyContextHandler
This interface defines the methods that must be implemented by handlers that are to be registered and activated by
the
PolicyContext
class.
The PolicyContext
class provides methods for containers to register and activate container-specific
PolicyContext
handlers. Policy
providers use the PolicyContext
class to
activate handlers to obtain (from the container) additional policy relevant context to apply in their access
decisions. All handlers registered and activated via the PolicyContext
class must implement the
PolicyContextHandler
interface.
- Author:
- Ron Monzillo, Gary Ellison
- See Also:
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Method Summary
Modifier and TypeMethodDescriptiongetContext
(String key, Object data) This public method is used by thePolicyContext
class to activate the handler and obtain from it the context object identified by the (case-sensitive) key.String[]
getKeys()
This public method returns the keys identifying the context objects supported by the handler.boolean
This public method returns a boolean result indicating whether or not the handler supports the context object identified by the (case-sensitive) key value.
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Method Details
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supports
This public method returns a boolean result indicating whether or not the handler supports the context object identified by the (case-sensitive) key value.- Parameters:
key
- aString
value identifying a context object that could be supported by the handler. The value of this parameter must not be null.- Returns:
- a boolean indicating whether or not the context object corresponding to the argument key is handled by the handler.
- Throws:
PolicyContextException
- if the implementation throws a checked exception that has not been accounted for by the method signature. The exception thrown by the implementation class will be encapsulated (during construction) in the thrown PolicyContextException
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getKeys
This public method returns the keys identifying the context objects supported by the handler. The value of each key supported by a handler must be a non-nullString
value.- Returns:
- an array containing
String
values identifying the context objects supported by the handler. The array must not contain duplicate key values. In the unlikely case that the Handler supports no keys, the handler must return a zero length array. The value null must never be returned by this method. - Throws:
PolicyContextException
- if the implementation throws a checked exception that has not been accounted for by the method signature. The exception thrown by the implementation class will be encapsulated (during construction) in the thrown PolicyContextException
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getContext
This public method is used by thePolicyContext
class to activate the handler and obtain from it the context object identified by the (case-sensitive) key. In addition to the key, the handler will be activated with the handler data value associated within thePolicyContext
class with the thread on which the call to this method is made.Note that the policy context identifier associated with a thread is available to the handler by calling PolicyContext.getContextID().
- Parameters:
key
- a String that identifies the context object to be returned by the handler. The value of this parameter must not be null.data
- the handler dataObject
associated with the thread on which the call to this method has been made. Note that the value passed through this parameter may benull
.- Returns:
- The container and handler specific
Object
containing the desired context. Anull
value may be returned if the value of the corresponding context is null. - Throws:
PolicyContextException
- if the implementation throws a checked exception that has not been accounted for by the method signature. The exception thrown by the implementation class will be encapsulated (during construction) in the thrown PolicyContextException
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