/* Copyright 2004, 2005 Acegi Technology Pty Limited
*
* 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.acegisecurity.vote;
import org.acegisecurity.AccessDeniedException;
import org.acegisecurity.Authentication;
import org.acegisecurity.ConfigAttributeDefinition;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.Iterator;
/**
* Simple concrete implementation of {@link
* org.acegisecurity.AccessDecisionManager} that uses a consensus-based
* approach.
*/
public class ConsensusBased extends AbstractAccessDecisionManager {
//~ Static fields/initializers =============================================
private static final Log logger = LogFactory.getLog(ConsensusBased.class);
//~ Instance fields ========================================================
private boolean allowIfEqualGrantedDeniedDecisions = true;
//~ Methods ================================================================
/**
* This concrete implementation simply polls all configured {@link
* AccessDecisionVoter}s and upon completion determines the consensus of
* granted vs denied responses.
*
* <p>
* If there were an equal number of grant and deny votes, the decision will
* be based on the {@link #isAllowIfEqualGrantedDeniedDecisions()}
* property (defaults to true).
* </p>
*
* <p>
* If every <code>AccessDecisionVoter</code> abstained from voting, the
* decision will be based on the {@link #isAllowIfAllAbstainDecisions()}
* property (defaults to false).
* </p>
*
* @param authentication the caller invoking the method
* @param object the secured object
* @param config the configuration attributes associated with the method
* being invoked
*
* @throws AccessDeniedException if access is denied
*/
public void decide(Authentication authentication, Object object,
ConfigAttributeDefinition config) throws AccessDeniedException {
Iterator iter = this.getDecisionVoters().iterator();
int grant = 0;
int deny = 0;
int abstain = 0;
while (iter.hasNext()) {
AccessDecisionVoter voter = (AccessDecisionVoter) iter.next();
int result = voter.vote(authentication, object, config);
switch (result) {
case AccessDecisionVoter.ACCESS_GRANTED:
grant++;
break;
case AccessDecisionVoter.ACCESS_DENIED:
deny++;
break;
default:
abstain++;
break;
}
}
if (grant > deny) {
return;
}
if (deny > grant) {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied",
"Access is denied"));
}
if ((grant == deny) && (grant != 0)) {
if (this.allowIfEqualGrantedDeniedDecisions) {
return;
} else {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied",
"Access is denied"));
}
}
// To get this far, every AccessDecisionVoter abstained
if (this.isAllowIfAllAbstainDecisions()) {
return;
} else {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied",
"Access is denied"));
}
}
public boolean isAllowIfEqualGrantedDeniedDecisions() {
return allowIfEqualGrantedDeniedDecisions;
}
public void setAllowIfEqualGrantedDeniedDecisions(
boolean allowIfEqualGrantedDeniedDecisions) {
this.allowIfEqualGrantedDeniedDecisions = allowIfEqualGrantedDeniedDecisions;
}
}