protections.java

aglet的部分源码

package com.ibm.aglet.security;

/*
 * @(#)Protections.java
 * 
 * (c) Copyright IBM Corp. 1998
 * 
 * IBM grants you a non-exclusive, non-transferrable License to
 * use this program internally solely for the purposes of testing
 * and evaluating Java Aglet API.
 * You may not distribute, sublicense, lease, rent or use this
 * sample program externally.
 * 
 * THIS ROGRAM IS PROVIDED "AS IS" WITHOUT ANY WARRANTY EXPRESS OR
 * IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE WARRANTY OF
 * NON-INFRINGEMENT AND THE WARRANTIES OF MERCHANTIBILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.
 * IBM WILL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY YOU AS
 * A RESULT OF USING THIS SAMPLE PROGRAM. IN NO EVENT WILL IBM BE
 * LIABLE FOR ANY SPECIAL, INDIRECT CONSEQUENTIAL DAMAGES OR LOST
 * PROFITS EVEN IF IBM HAS BEEN ADVISED OF THE POSSIBILITY OF THEIR
 * OCCURRENCE OR LOSS OF OR DAMAGE TO YOUR RECORDS OR DATA.
 * IBM WILL NOT BE LIABLE FOR ANY THIRD PARTY CLAIMS AGAINST YOU.
 */

import java.security.Permission;
import java.security.Permissions;
import java.security.PermissionCollection;

import java.io.Serializable;
import java.util.Vector;
import java.util.Enumeration;

/**
 * The <tt>Protections</tt> class is a Permissions who contains
 * only AgletProtections or MessageProtections.
 * 
 * @version     1.00    $Date: 2001/07/28 06:34:15 $
 * @author      ONO Kouichi
 */
public class Protections extends PermissionCollection 
	implements Serializable {
	private Vector pset = new Vector();

	public Protections() {
		super();
	}
	synchronized public void add(Permission p) {
		if (p == null) {
			return;
		} 
		if (isReadOnly()) {
			throw new SecurityException("attempt to add a Protection to a readonly Protections object");
		} 
		if (p instanceof Protection) {
			pset.addElement(p);
		} 
	}
	public Enumeration elements() {
		return pset.elements();
	}
	public boolean implies(Permission p) {
		if (p instanceof com.ibm.aglet.security.AgletProtection) {
			for (Enumeration e = pset.elements(); e.hasMoreElements(); ) {
				Permission t = (Permission)e.nextElement();
				if (t instanceof com.ibm.aglet.security.AgletProtection) {
					if (!t.implies(p)) {
						return false;
					}
				}
			}
		} else {
			for (Enumeration e = pset.elements(); e.hasMoreElements(); ) {
				Permission t = (Permission)e.nextElement();
				if (t instanceof com.ibm.aglet.security.MessageProtection) {
					if (!t.implies(p)) {
						return false;
					}
				}
			}
		} 
		return true;
	}
}