sipcallpermissioncollection.java

First of all, the Applet-phone is a SIP User-Agent with audio and text messaging capabilities. But

/*
 * SipCallPermissionCollection.java
 *
 * Created on June 18, 2003, 10:27 AM
 */

package gov.nist.security.permissions;

import java.security.*;
import java.util.*;

/**
 * Class representing a collection of SipCallPermission
 * @author  DERUELLE Jean
 */
public class SipCallPermissionCollection extends PermissionCollection {
    /**set of SipCallPermissions*/
    private Hashtable permissions;
    private boolean addedAdmin;
    /**mask of the actions*/
    private int adminMask;
    
    /** 
     * Creates a new instance of SipCallPermissionCollection
     */
    SipCallPermissionCollection() {
            permissions = new Hashtable();
            addedAdmin = false;
    }

    /**
     * Add a permission to the existing set of permission
     * @param p - the permission to add
     */
    public void add(Permission p) {
            if (!(p instanceof SipCallPermission))
                    throw new IllegalArgumentException("Wrong permission type");
            SipCallPermission sipCallPermission = (SipCallPermission) p;
            String name = sipCallPermission.getName();
            SipCallPermission other =(SipCallPermission) permissions.get(name);
            if (other != null)
                    sipCallPermission = merge(sipCallPermission, other);
            if (name.equals("*")) {
                    addedAdmin = true;
                    adminMask = sipCallPermission.mask;
            }
            permissions.put(name, sipCallPermission);
    }

    /**
     * return the permissions of the collection
     * @return the permissions of the collection
     */
    public Enumeration elements() {
            return permissions.elements();
    }

    /**
     * Checks if the specified permission's actions are "implied by" this object's actions.
     * @param p - the permission to check against.
     * @return if the specified permission is implied by this object, false if not. 
     */
    public boolean implies(Permission p) {
            if (!(p instanceof SipCallPermission))
                    return false;
            SipCallPermission sipCallPermission = (SipCallPermission) p;
            if (addedAdmin && (adminMask & sipCallPermission.mask) == sipCallPermission.mask)
                    return true;
            Permission inTable = (Permission)permissions.get(sipCallPermission.getName());
            if (inTable == null)
                    return false;
            return inTable.implies(sipCallPermission);
    }

    /**
     * merge the two permissions
     * @param a - permssion to merge
     * @param b - permission to merge
     * @return the new permission created on the merging of the two permissions
     */
    private SipCallPermission merge(SipCallPermission a, SipCallPermission b) {
            String aAction = a.getActions();
            if (aAction.equals(""))
                    return b;
            String bAction = b.getActions();
            if (bAction.equals(""))
                    return a;
            return new SipCallPermission(a.getName(),aAction + "," + bAction);
    }
}