UnresolvedPermission JDK 1.6)

Description

publicfinal class UnresolvedPermission

The UnresolvedPermission class is used to hold Permissions that were "unresolved" when the Policy was initialized.

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.

Note that the getName method for an UnresolvedPermission returns the type (class name) for the underlying permission that has not been resolved.

See also: Permission Permissions PermissionCollection Policy

Methods

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public void checkGuard (Object object) throws SecurityException [Inherited From Permission]

Implements the guard interface for a permission.

Implements the guard interface for a permission. The
SecurityManager.checkPermission method is called,
passing this permission object as the permission to check.
Returns silently if access is granted. Otherwise, throws
a SecurityException.
Parameters:
- object - the object being guarded (currently ignored).
Throws:
- SecurityException - if a security manager exists and its checkPermission method doesn't allow access.
See Also: Guard, GuardedObject, SecurityManager.checkPermission(java.security.Permission),

public boolean equals (Object obj) [Specified in Permission]

Checks two UnresolvedPermission objects for equality.

public String getActions () [Specified in Permission]

Returns the canonical string representation of the actions, which currently is the empty string "", since there are no actions for an UnresolvedPermission.

publicfinal String getName () [Inherited From Permission]

Returns the name of this Permission.

Returns the name of this Permission.
For example, in the case of a java.io.FilePermission,
the name will be a pathname.
Returns: the name of this Permission.

public String getUnresolvedActions ()

Get the actions for the underlying permission that has not been resolved.

Get the actions for the underlying permission that
has not been resolved.
Returns: the actions for the underlying permission that has not been resolved, or null if there are no actions
Since: 1.5

public Certificate getUnresolvedCerts ()

Get the signer certificates (without any supporting chain) for the underlying permission that has not been resolved.

public String getUnresolvedName ()

Get the target name of the underlying permission that has not been resolved.

Get the target name of the underlying permission that
has not been resolved.
Returns: the target name of the underlying permission that has not been resolved, or null, if there is no targe name
Since: 1.5

public String getUnresolvedType ()

Get the type (class name) of the underlying permission that has not been resolved.

public int hashCode () [Specified in Permission]

Returns the hash code value for this object.

public boolean implies (Permission p) [Specified in Permission]

This method always returns false for unresolved permissions.

public PermissionCollection newPermissionCollection () [Overrides Permission]

Returns a new PermissionCollection object for storing UnresolvedPermission objects.

pack-private Permission resolve (Permission p, Certificate certs)

try and resolve this permission using the class loader of the permission that was passed in.

public String toString () [Overrides Permission]

Returns a string describing this UnresolvedPermission.