- All Implemented Interfaces:
- Serializable
- Direct Known Subclasses:
- Permissions
With a PermissionCollection, you can:
 
-  add a permission to the collection using the addmethod.
-  check to see if a particular permission is implied in the
      collection, using the impliesmethod.
-  enumerate all the permissions, using the elementsmethod.
When it is desirable to group together a number of Permission
 objects of the same type, the newPermissionCollection method on that
 particular type of Permission object should first be called. The
 default behavior (from the Permission class) is to simply return
 null. Subclasses of class Permission override the method if
 they need to store their permissions in a particular
 PermissionCollection object in order to provide the correct
 semantics when the PermissionCollection.implies method is called.
 If a non-null value is returned, that PermissionCollection must be
 used. If null is returned, then the caller of
 newPermissionCollection is free to store permissions of the
 given type in any PermissionCollection they choose
 (one that uses a Hashtable, one that uses a Vector, etc.).
 
The collection returned by the Permission.newPermissionCollection
 method is a homogeneous collection, which stores only Permission
 objects for a given permission type.  A PermissionCollection may
 also be heterogeneous.  For example, Permissions is a
 PermissionCollection subclass that represents a collection of
 PermissionCollection objects.
 That is, its members are each a homogeneous PermissionCollection.
 For example, a Permission object might have a
 FilePermissionCollection for all the FilePermission objects,
 a SocketPermissionCollection for all the SocketPermission
 objects, and so on. Its add method adds a
 permission to the appropriate collection.
 
Whenever a permission is added to a heterogeneous
 PermissionCollection such as Permissions, and the
 PermissionCollection doesn't yet contain a
 PermissionCollection of the specified permission's type, the
 PermissionCollection should call
 the newPermissionCollection method on the permission's class
 to see if it requires a special PermissionCollection. If
 newPermissionCollection
 returns null, the PermissionCollection
 is free to store the permission in any type of PermissionCollection
 it desires (one using a Hashtable, one using a Vector, etc.).
 For example, the Permissions object uses a default
 PermissionCollection implementation that stores the permission
 objects in a Hashtable.
 
 Subclass implementations of PermissionCollection should assume
 that they may be called simultaneously from multiple threads,
 and therefore should be synchronized properly.  Furthermore,
 Enumerations returned via the elements method are
 not fail-fast.  Modifications to a collection should not be
 performed while enumerating over that collection.
- Since:
- 1.2
- See Also:
- 
Constructor SummaryConstructors
- 
Method SummaryModifier and TypeMethodDescriptionabstract voidadd(Permission permission) Adds a permission object to the current collection of permission objects.abstract Enumeration<Permission> elements()Returns an enumeration of all the Permission objects in the collection.Returns a stream of all the Permission objects in the collection.abstract booleanimplies(Permission permission) Checks to see if the specified permission is implied by the collection ofPermissionobjects held in thisPermissionCollection.booleanReturnstrueif thisPermissionCollectionobject is marked as readonly.voidMarks thisPermissionCollectionobject as "readonly".toString()Returns a string describing thisPermissionCollectionobject, providing information about all the permissions it contains.
- 
Constructor Details- 
PermissionCollectionpublic PermissionCollection()Constructor for subclasses to call.
 
- 
- 
Method Details- 
addAdds a permission object to the current collection of permission objects.- Parameters:
- permission- the Permission object to add.
- Throws:
- SecurityException- if this- PermissionCollectionobject has been marked readonly
- IllegalArgumentException- if this- PermissionCollectionobject is a homogeneous collection and the permission is not of the correct type.
 
- 
impliesChecks to see if the specified permission is implied by the collection ofPermissionobjects held in thisPermissionCollection.- Parameters:
- permission- the- Permissionobject to compare.
- Returns:
- trueif "permission" is implied by the permissions in the collection,- falseif not.
 
- 
elementsReturns an enumeration of all the Permission objects in the collection.- Returns:
- an enumeration of all the Permissions.
- See Also:
 
- 
elementsAsStreamReturns a stream of all the Permission objects in the collection.The collection should not be modified (see add(java.security.Permission)) during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.- Implementation Requirements:
- The default implementation creates a stream whose source is derived from
 the enumeration returned from a call to elements().
- Returns:
- a stream of all the Permissions.
- Since:
- 9
 
- 
setReadOnlypublic void setReadOnly()Marks thisPermissionCollectionobject as "readonly". After aPermissionCollectionobject is marked as readonly, no newPermissionobjects can be added to it usingadd.
- 
isReadOnlypublic boolean isReadOnly()Returnstrueif thisPermissionCollectionobject is marked as readonly. If it is readonly, no newPermissionobjects can be added to it usingadd.By default, the object is not readonly. It can be set to readonly by a call to setReadOnly.- Returns:
- trueif this- PermissionCollectionobject is marked as readonly,- falseotherwise.
 
- 
toStringReturns a string describing thisPermissionCollectionobject, providing information about all the permissions it contains. The format is:super.toString() ( // enumerate all the Permission // objects and call toString() on them, // one per line.. ) super.toStringis a call to thetoStringmethod of this object's superclass, which isObject. The result is this collection's type name followed by this object's hashcode, thus enabling clients to differentiate differentPermissionCollectionobjects, even if they contain the same permissions.
 
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