org.osgi.service.condpermadmin
Interface Condition

All Known Implementing Classes:

UserPromptCondition

public interface Condition

The interface implemented by a Condition. Conditions are bound to Permissions using Conditional Permission Info. The Permissions of a ConditionalPermission Info can only be used if the associated Conditions are satisfied.

ThreadSafe

Field Summary

static Condition	FALSE A Condition object that will always evaluate to false and that is never postponed.
static Condition	TRUE A Condition object that will always evaluate to true and that is never postponed.

Method Summary

boolean	isMutable() Returns whether the Condition is mutable.
boolean	isPostponed() Returns whether the evaluation must be postponed until the end of the permission check.
boolean	isSatisfied() Returns whether the Condition is satisfied.
boolean	isSatisfied(Condition[] conditions, java.util.Dictionary context) Returns whether a the set of Condition objects are satisfied.

Field Detail

TRUE

static final Condition TRUE

A Condition object that will always evaluate to true and that is never postponed.

FALSE

static final Condition FALSE

A Condition object that will always evaluate to false and that is never postponed.

Method Detail

isPostponed

boolean isPostponed()

Returns whether the evaluation must be postponed until the end of the permission check. If this method returns false (or this Condition is immutable), then this Condition must be able to directly answer the isSatisfied() method. In other words, isSatisfied() will return very quickly since no external sources, such as for example users or networks, need to be consulted.
This method must always return the same value whenever it is called so that the Conditional Permission Admin can cache its result.

Returns:

true to indicate the evaluation must be postponed. Otherwise, false if the evaluation can be performed immediately.

isSatisfied

boolean isSatisfied()

Returns whether the Condition is satisfied. This method is only called for immediate Condition objects or immutable postponed conditions, and must always be called inside a permission check. Mutable postponed Condition objects will be called with the grouped version isSatisfied(Condition[],Dictionary) at the end of the permission check.

Returns:

true to indicate the Conditions is satisfied. Otherwise, false if the Condition is not satisfied.

isMutable

boolean isMutable()

Returns whether the Condition is mutable. A Condition can go from mutable (true) to immutable (false) over time but never from immutable (false) to mutable (true).

Returns:

true isSatisfied() can change. Otherwise, false if the value returned by isSatisfied() will not change for this condition.

isSatisfied

boolean isSatisfied(Condition[] conditions,
                    java.util.Dictionary context)

Returns whether a the set of Condition objects are satisfied. Although this method is not static, it must be implemented as if it were static. All of the passed Condition objects will be of the same type and will correspond to the class type of the object on which this method is invoked.This method must be called inside a permission check only.

Parameters:

conditions - The array of Condition objects, which must all be of the same class and mutable. The receiver must be one of those Condition objects.

context - A Dictionary object that implementors can use to track state. If this method is invoked multiple times in the same permission check, the same Dictionary will be passed multiple times. The SecurityManager treats this Dictionary as an opaque object and simply creates an empty dictionary and passes it to subsequent invocations if multiple invocations are needed.

Returns:

true if all the Condition objects are satisfied. Otherwise, false if one of the Condition objects is not satisfied.