JavaTM 2 Platform Std. Ed. v1.4.2
java.security
Class UnresolvedPermission
java.lang.Object
java.security.Permission
java.security.UnresolvedPermission
- All Implemented Interfaces:
- Guard, Serializable
- public final class UnresolvedPermission
- extends Permission
- implements Serializable
The UnresolvedPermission class is used to hold Permissions that
were "unresolved" when the Policy was initialized.
An unresolved permission is one whose actual Permission class
does not yet exist at the time the Policy is initialized (see below).
The policy for a Java runtime (specifying
which permissions are available for code from various principals)
is represented by a Policy object.
Whenever a Policy is initialized or refreshed, Permission objects of
appropriate classes are created for all permissions
allowed by the Policy.
Many permission class types
referenced by the policy configuration are ones that exist
locally (i.e., ones that can be found on CLASSPATH).
Objects for such permissions can be instantiated during
Policy initialization. For example, it is always possible
to instantiate a java.io.FilePermission, since the
FilePermission class is found on the CLASSPATH.
Other permission classes may not yet exist during Policy
initialization. For example, a referenced permission class may
be in a JAR file that will later be loaded.
For each such class, an UnresolvedPermission is instantiated.
Thus, an UnresolvedPermission is essentially a "placeholder"
containing information about the permission.
Later, when code calls AccessController.checkPermission
on a permission of a type that was previously unresolved,
but whose class has since been loaded, previously-unresolved
permissions of that type are "resolved". That is,
for each such UnresolvedPermission, a new object of
the appropriate class type is instantiated, based on the
information in the UnresolvedPermission.
To instantiate the new class, UnresolvedPermission assumes
the class provides a zero, one, and/or two-argument constructor.
The zero-argument constructor would be used to instantiate
a permission without a name and without actions.
A one-arg constructor is assumed to take a String
name as input, and a two-arg constructor is assumed to take a
String name and String actions
as input. UnresolvedPermission may invoke a
constructor with a null name and/or actions.
If an appropriate permission constructor is not available,
the UnresolvedPermission is ignored and the relevant permission
will not be granted to executing code.
The newly created permission object replaces the
UnresolvedPermission, which is removed.
- See Also:
Permission ,
Permissions ,
PermissionCollection ,
Policy ,
Serialized Form
Constructor Summary |
UnresolvedPermission(String type,
String name,
String actions,
Certificate[] certs)
Creates a new UnresolvedPermission containing the permission
information needed later to actually create a Permission of the
specified class, when the permission is resolved. |
Method Summary |
boolean |
equals(Object obj)
Checks two UnresolvedPermission objects for equality. |
String |
getActions()
Returns the canonical string representation of the actions,
which currently is the empty string "", since there are no actions for
an UnresolvedPermission. |
int |
hashCode()
Returns the hash code value for this object. |
boolean |
implies(Permission p)
This method always returns false for unresolved permissions. |
PermissionCollection |
newPermissionCollection()
Returns a new PermissionCollection object for storing
UnresolvedPermission objects. |
String |
toString()
Returns a string describing this UnresolvedPermission. |
UnresolvedPermission
public UnresolvedPermission(String type,
String name,
String actions,
Certificate[] certs)
- Creates a new UnresolvedPermission containing the permission
information needed later to actually create a Permission of the
specified class, when the permission is resolved.
- Parameters:
type - the class name of the Permission class that will be
created when this unresolved permission is resolved.name - the name of the permission.actions - the actions of the permission.certs - the certificates the permission's class was signed with.
This is a list of certificate chains, where each chain is composed of a
signer certificate and optionally its supporting certificate chain.
Each chain is ordered bottom-to-top (i.e., with the signer certificate
first and the (root) certificate authority last).
implies
public boolean implies(Permission p)
- This method always returns false for unresolved permissions.
That is, an UnresolvedPermission is never considered to
imply another permission.
- Specified by:
implies in class Permission
- Parameters:
p - the permission to check against.
- Returns:
- false.
equals
public boolean equals(Object obj)
- Checks two UnresolvedPermission objects for equality.
Checks that obj is an UnresolvedPermission, and has
the same type (class) name, permission name, actions, and
certificates as this object.
- Specified by:
equals in class Permission
- Parameters:
obj - the object we are testing for equality with this object.
- Returns:
- true if obj is an UnresolvedPermission, and has the same
type (class) name, permission name, actions, and
certificates as this object.
hashCode
public int hashCode()
- Returns the hash code value for this object.
- Specified by:
hashCode in class Permission
- Returns:
- a hash code value for this object.
getActions
public String getActions()
- Returns the canonical string representation of the actions,
which currently is the empty string "", since there are no actions for
an UnresolvedPermission. That is, the actions for the
permission that will be created when this UnresolvedPermission
is resolved may be non-null, but an UnresolvedPermission
itself is never considered to have any actions.
- Specified by:
getActions in class Permission
- Returns:
- the empty string "".
toString
public String toString()
- Returns a string describing this UnresolvedPermission. The convention
is to specify the class name, the permission name, and the actions, in
the following format: '(unresolved "ClassName" "name" "actions")'.
- Overrides:
toString in class Permission
- Returns:
- information about this UnresolvedPermission.
newPermissionCollection
public PermissionCollection newPermissionCollection()
- Returns a new PermissionCollection object for storing
UnresolvedPermission objects.
- Overrides:
newPermissionCollection in class Permission
- Returns:
- a new PermissionCollection object suitable for
storing UnresolvedPermissions.
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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