src/org/apache/policy/util/PolicyRegistry.java

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.policy.util;

import java.util.HashMap;
import java.util.Iterator;

import org.apache.policy.model.Policy;

/**
 * PolicyRegistry is contains reference to external policy that are used by the
 * policy model to resolve policy reference objects to their actual policies.
 * 
 */
public class PolicyRegistry {
	HashMap     reg    = new HashMap ();
	PolicyRegistry parent = null;
	
	public PolicyRegistry () {
	}
	
	public PolicyRegistry (PolicyRegistry parent) {
		this.parent = parent;
	}
	
	public Policy lookup (String policyURI) throws IllegalArgumentException {
		
		Policy policy =  (Policy) reg.get (policyURI);

		if (policy == null && parent != null) {
		  policy = parent.lookup (policyURI);
		}

//		if (policy == null) {
//		  throw new IllegalArgumentException ("policy '" + policyURI + "' not in registry");
//		}

		return policy;
	  }
	  // register a policy
	  public void register (String policyURI, Policy policy) {
		reg.put (policyURI, policy);
	  }
	  
	  // unregister a policy
	  public void unregister (String policyURI) {
		reg.remove (policyURI);
	  }
	  
	  public Iterator keys() {
	  	return reg.keySet().iterator();
	  }
	  
	  public Iterator values() {
	  	return reg.values().iterator();
	  }  	  
}