JSPWiki - a JSP-based WikiWiki clone.
Copyright (C) 2001-2002 Janne Jalkanen (Janne.Jalkanen@iki.fi)
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* Defines an access control list (ACL) for wiki pages. An Access Control List
* is a data structure used to guard access to resources. An ACL can be thought
* of as a data structure with multiple ACL entries. Each ACL entry, of
* interface type AclEntry, contains a set of positive permissions associated
* with a particular principal. (A principal represents an entity such as an
* individual user or a group). The ACL Entries in each ACL observe the
* following rules:
* <li>Each principal can have at most one ACL entry; that is, multiple ACL
* entries are not allowed for any principal. Each entry specifies the set of
* permissions that are to be granted</li>
* <li>If there is no entry for a particular principal, then the principal is
* considered to have a null (empty) permission set</li>
* This interface is a highly stripped-down derivation of the
* java.security.acl.Acl interface. In particular, the notion of an Acl "owner"
* has been eliminated, since JWPWiki pages do not have owners. An additional
* simplification compared to the standard Java package is that negative
* permissions have been eliminated. Instead, JSPWiki assumes a "default-deny"
* security stance: principals are granted no permissions by default, and
* posesses only those that have been explicitly granted to them. And finally,
* the getPermissions() and checkPermission() methods have been eliminated due
* to the complexities associated with resolving Role principal membership.
* @author Janne Jalkanen
* @author Andrew Jaquith
* @since 2.3
public interface Acl
* Adds an ACL entry to this ACL. An entry associates a principal (e.g., an
* individual or a group) with a set of permissions. Each principal can have
* at most one positive ACL entry, specifying permissions to be granted to
* the principal. If there is already an ACL entry already in the ACL, false
* is returned.
* @param entry - the ACL entry to be added to this ACL
* @return true on success, false if an entry of the same type (positive or
* negative) for the same principal is already present in this ACL
public boolean addEntry( AclEntry entry );
* Returns an enumeration of the entries in this ACL. Each element in the
* enumeration is of type AclEntry.
* @return an enumeration of the entries in this ACL.
public Enumeration entries();
* Returns <code>true</code>, if this Acl is empty.
* @return the result
* @since 2.4.68
public boolean isEmpty();
* Returns all Principal objects assigned a given Permission in the access
* control list. The Princiapls returned are those that have been granted
* either the supplied permission, or a permission implied by the supplied
* permission. Principals are not "expanded" if they are a role or group.
* @param permission the permission to search for
* @return an array of Principals posessing the permission
public Principal findPrincipals( Permission permission );
* Returns an AclEntry for a supplied Principal, or <code>null</code> if
* the Principal does not have a matching AclEntry.
* @param principal the principal to search for
* @return the AclEntry associated with the principal, or <code>null</code>
public AclEntry getEntry( Principal principal );
* Removes an ACL entry from this ACL.
* @param entry the ACL entry to be removed from this ACL
* @return true on success, false if the entry is not part of this ACL
public boolean removeEntry( AclEntry entry );
* Returns a string representation of the contents of this Acl.
* @return the string representation
public String toString();