javax.security.auth

Class PrivateCredentialPermission

Implemented Interfaces:
Guard, Serializable

public final class PrivateCredentialPermission
extends Permission
implements Serializable

A permission governing access to a private credential. The action of this permission is always "read" -- meaning that the private credential information can be read from an object.

The target of this permission is formatted as follows:

CredentialClassName ( PrinicpalClassName PrincipalName )*

CredentialClassName is either the name of a private credential class name, or a wildcard character ('*'). PrinicpalClassName is the class name of a principal object, and PrincipalName is a string representing the principal, or the wildcard character.

See Also:
Serialized Form

Constructor Summary

PrivateCredentialPermission(String name, String actions)
Create a new private credential permission.

Method Summary

boolean
equals(Object o)
Determine whether this Object is semantically equal to another Object.
String
getActions()
Returns the actions this permission encompasses.
String
getCredentialClass()
Returns the credential class name that was embedded in this permission's target name.
String[][]
getPrincipals()
Returns the principal list that was embedded in this permission's target name.
int
hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.
boolean
implies(Permission p)
Test if this permission implies another.
PermissionCollection
newPermissionCollection()
This method is not necessary for this class, thus it always returns null.

Methods inherited from class java.security.Permission

checkGuard, equals, getActions, getName, hashCode, implies, newPermissionCollection, toString

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PrivateCredentialPermission

public PrivateCredentialPermission(String name,
                                   String actions)
Create a new private credential permission.
Parameters:
name - The permission target name.
actions - The list of actions, which, for this class, must be "read".

Method Details

equals

public boolean equals(Object o)
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

  • It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
  • It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
  • It must be reflexive. a.equals(a) must always be true.
  • It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
  • a.equals(null) must be false.
  • It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:
equals in interface Permission
Parameters:
Returns:
whether this Object is semantically equal to another

getActions

public String getActions()
Returns the actions this permission encompasses. For private credential permissions, this is always the string "read".
Overrides:
getActions in interface Permission
Returns:
The list of actions.

getCredentialClass

public String getCredentialClass()
Returns the credential class name that was embedded in this permission's target name.
Returns:
The credential class name.

getPrincipals

public String[][] getPrincipals()
Returns the principal list that was embedded in this permission's target name.

Each element of the returned array is a pair; the first element is the principal class name, and the second is the principal name.

Returns:
The principal list.

hashCode

public int hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

  • Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
  • It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:
hashCode in interface Permission
Returns:
the hash code for this Object

implies

public boolean implies(Permission p)
Test if this permission implies another. This method returns true if:
  1. p is an instance of PrivateCredentialPermission
  2. The credential class name of this instance matches that of p, and one of the principals of p is contained in the principals of this class. Thus,
    • [ * P "foo" ] implies [ C P "foo" ]
    • [ C P1 "foo" ] implies [ C P1 "foo" P2 "bar" ]
    • [ C P1 "*" ] implies [ C P1 "foo" ]
    Overrides:
    implies in interface Permission
    Parameters:
    p - The permission to check.
    Returns:
    True if this permission implies p.

    newPermissionCollection

    public PermissionCollection newPermissionCollection()
    This method is not necessary for this class, thus it always returns null.
    Overrides:
    newPermissionCollection in interface Permission
    Returns:
    null.

    PrivateCredentialPermission.java -- permissions governing private credentials. Copyright (C) 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.