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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.jmx.snmp.IPAcl;

import java.security.acl.Permission;

import java.util.Vector;

import java.util.Enumeration;

import java.io.Serializable;

import java.net.UnknownHostException;

import java.security.Principal;

import java.security.acl.AclEntry;

/**

 * Represent one entry in the Access Control List (ACL).

 * This ACL entry object contains a permission associated with a particular principal.

 * (A principal represents an entity such as an individual machine or a group).

 *

 * @see java.security.acl.AclEntry

 */

class AclEntryImpl implements AclEntry, Serializable {

  private static final long serialVersionUID = -5047185131260073216L;

  private AclEntryImpl (AclEntryImpl i) throws UnknownHostException {

        setPrincipal(i.getPrincipal());

        permList = new Vector<Permission>();

        commList = new Vector<String>();

        for (Enumeration<String> en = i.communities(); en.hasMoreElements();){

          addCommunity(en.nextElement());

        }

        for (Enumeration<Permission> en = i.permissions(); en.hasMoreElements();){

          addPermission(en.nextElement());

        }

        if (i.isNegative()) setNegativePermissions();

  }

  /**

   * Contructs an empty ACL entry.

   */

  public AclEntryImpl (){

        princ = null;

        permList = new Vector<Permission>();

        commList = new Vector<String>();

  }

  /**

   * Constructs an ACL entry with a specified principal.

   *

   * @param p the principal to be set for this entry.

   */

  public AclEntryImpl (Principal p) throws UnknownHostException {

        princ = p;

        permList = new Vector<Permission>();

        commList = new Vector<String>();

  }

  /**

   * Clones this ACL entry.

   *

   * @return a clone of this ACL entry.

   */

  public Object clone() {

        AclEntryImpl i;

        try {

          i = new AclEntryImpl(this);

        }catch (UnknownHostException e) {

          i = null;

        }

        return (Object) i;

  }

  /**

   * Returns true if this is a negative ACL entry (one denying the associated principal

   * the set of permissions in the entry), false otherwise.

   *

   * @return true if this is a negative ACL entry, false if it's not.

   */

  public boolean isNegative(){

        return neg;

  }

  /**

   * Adds the specified permission to this ACL entry. Note: An entry can

   * have multiple permissions.

   *

   * @param perm the permission to be associated with the principal in this

   *        entry

   * @return true if the permission is removed, false if the permission was

   *         not part of this entry's permission set.

   *

   */

  public boolean addPermission(java.security.acl.Permission perm){

        if (permList.contains(perm)) return false;

        permList.addElement(perm);

        return true;

  }

  /**

   * Removes the specified permission from this ACL entry.

   *

   * @param perm the permission to be removed from this entry.

   * @return true if the permission is removed, false if the permission

   *         was not part of this entry's permission set.

   */

  public boolean removePermission(java.security.acl.Permission perm){

        if (!permList.contains(perm)) return false;

        permList.removeElement(perm);

        return true;

  }

  /**

   * Checks if the specified permission is part of the permission set in

   * this entry.

   *

   * @param perm the permission to be checked for.

   * @return true if the permission is part of the permission set in this

   *         entry, false otherwise.

   */

  public boolean checkPermission(java.security.acl.Permission perm){

        return (permList.contains(perm));

  }

  /**

   * Returns an enumeration of the permissions in this ACL entry.

   *

   * @return an enumeration of the permissions in this ACL entry.

   */

  public Enumeration<Permission> permissions(){

        return permList.elements();

  }

  /**

   * Sets this ACL entry to be a negative one. That is, the associated principal

   * (e.g., a user or a group) will be denied the permission set specified in the

   * entry. Note: ACL entries are by default positive. An entry becomes a negative

   * entry only if this setNegativePermissions method is called on it.

   *

   * Not Implemented.

   */

  public void setNegativePermissions(){

        neg = true;

  }

  /**

   * Returns the principal for which permissions are granted or denied by this ACL

   * entry. Returns null if there is no principal set for this entry yet.

   *

   * @return the principal associated with this entry.

   */

  public Principal getPrincipal(){

        return princ;

  }

  /**

   * Specifies the principal for which permissions are granted or denied by

   * this ACL entry. If a principal was already set for this ACL entry,

   * false is returned, otherwise true is returned.

   *

   * @param p the principal to be set for this entry.

   * @return true if the principal is set, false if there was already a

   *         principal set for this entry.

   */

  public boolean setPrincipal(Principal p) {

        if (princ != null )

          return false;

        princ = p;

        return true;

  }

  /**

   * Returns a string representation of the contents of this ACL entry.

   *

   * @return a string representation of the contents.

   */

  public String toString(){

        return "AclEntry:"+princ.toString();

  }

  /**

   * Returns an enumeration of the communities in this ACL entry.

   *

   * @return an enumeration of the communities in this ACL entry.

   */

  public Enumeration<String> communities(){

        return commList.elements();

  }

  /**

   * Adds the specified community to this ACL entry. Note: An entry can

   * have multiple communities.

   *

   * @param comm the community to be associated with the principal

   *        in this entry.

   * @return true if the community was added, false if the community was

   *         already part of this entry's community set.

   */

  public boolean addCommunity(String comm){

        if (commList.contains(comm)) return false;

        commList.addElement(comm);

        return true;

  }

  /**

   * Removes the specified community from this ACL entry.

   *

   * @param comm the community  to be removed from this entry.

   * @return true if the community is removed, false if the community was

   *         not part of this entry's community set.

   */

  public boolean removeCommunity(String comm){

        if (!commList.contains(comm)) return false;

        commList.removeElement(comm);

        return true;

  }

  /**

   * Checks if the specified community is part of the community set in this

   * entry.

   *

   * @param  comm the community to be checked for.

   * @return true if the community is part of the community set in this

   *         entry, false otherwise.

   */

  public boolean checkCommunity(String comm){

        return (commList.contains(comm));

  }

  private Principal princ = null;

  private boolean neg     = false;

  private Vector<Permission> permList = null;

  private Vector<String> commList = null;

}