| /* Permission.java -- The superclass for all permission objects |
| Copyright (C) 1998 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| As a special exception, if you link this library with other files to |
| produce an executable, this library does not by itself cause the |
| resulting executable to be covered by the GNU General Public License. |
| This exception does not however invalidate any other reasons why the |
| executable file might be covered by the GNU General Public License. */ |
| |
| |
| package java.security; |
| |
| import java.io.Serializable; |
| |
| /** |
| * This class is the abstract superclass of all classes that implement |
| * the concept of a permission. A permission consists of a permission name |
| * and optionally a list of actions that relate to the permission. The |
| * actual meaning of the name of the permission is defined only in the |
| * context of a subclass. It may name a resource to which access permissions |
| * are granted (for example, the name of a file) or it might represent |
| * something else entirely. Similarly, the action list only has meaning |
| * within the context of a subclass. Some permission names may have no |
| * actions associated with them. That is, you either have the permission |
| * or you don't. |
| * |
| * The most important method in this class is <code>implies</code>. This |
| * checks whether if one has this permission, then the specified |
| * permission is also implied. As a conceptual example, consider the |
| * permissions "Read All Files" and "Read File foo". The permission |
| * "Read All Files" implies that the caller has permission to read the |
| * file foo. |
| * |
| * <code>Permission</code>'s are not dynamic objects. Once created, a |
| * <code>Permission</code>'s name and action list cannot be changed. |
| * |
| * @version 0.0 |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| */ |
| public abstract class Permission implements Guard, Serializable |
| { |
| |
| /*************************************************************************/ |
| |
| /* |
| * Instance Variables |
| */ |
| |
| /** |
| * This is the name assigned to this permission object. |
| */ |
| protected String name; // Taken from the serializable form information |
| |
| /*************************************************************************/ |
| |
| /* |
| * Constructors |
| */ |
| |
| /** |
| * This method initializes a new instance of <code>Permission</code> to |
| * have the specified name. |
| */ |
| public |
| Permission(String name) |
| { |
| this.name = name; |
| } |
| |
| /*************************************************************************/ |
| |
| /* |
| * Instance Methods |
| */ |
| |
| /** |
| * This method returns the name of this <code>Permission</code> |
| * |
| * @return The name of this <code>Permission</code> |
| */ |
| public String |
| getName() |
| { |
| return(name); |
| } |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method returns the list of actions for this <code>Permission</code> |
| * as a <code>String</code>. |
| * |
| * @return The action list for this <code>Permission</code>. |
| */ |
| public abstract String |
| getActions(); |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method implements the <code>Guard</code> interface for this class. |
| * It calls the <code>checkPermission</code> method in |
| * <code>SecurityManager</code> with this <code>Permission</code> as its |
| * argument. This method returns silently if the security check succeeds |
| * or throws an exception if it fails. |
| * |
| * @param obj The <code>Object</code> being guarded - ignored by this class |
| * |
| * @exception SecurityException If the security check fails |
| */ |
| public void |
| checkGuard(Object obj) throws SecurityException |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| // if (sm != null) |
| // sm.checkPermission(this); |
| } |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method tests whether this <code>Permission</code> implies that the |
| * specified <code>Permission</code> is also granted. |
| * |
| * @param perm The <code>Permission</code> to test against |
| * |
| * @return <code>true</code> if the specified <code>Permission</code> is implied by this one, <code>false</code> otherwise. |
| */ |
| public abstract boolean |
| implies(Permission perm); |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method returns a hash code for this <code>Permission</code>. |
| * |
| * @return A hash value. |
| */ |
| public abstract int |
| hashCode(); |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method returns a <code>String</code> representation of this |
| * <code>Permission</code> object. |
| * |
| * @return This object as a <code>String</code>. |
| */ |
| public String |
| toString() |
| { |
| return("'\"" + getClass().getName() + "\" \"" + getName() + |
| "\"" + " \"" + getActions() + "\")'"); |
| } |
| |
| /*************************************************************************/ |
| |
| /** |
| * This method returns an empty <code>PermissionCollection</code> object |
| * that can store permissions of this type, or <code>null</code> if no |
| * such collection is defined. |
| * |
| * @return A new <code>PermissionCollection</code> |
| */ |
| public PermissionCollection |
| newPermissionCollection() |
| { |
| return(null); |
| } |
| |
| } // class Permission |
| |