org.apache.neethi.AbstractPolicyOperator Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.neethi;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.neethi.util.PolicyComparator;
/**
* AbstractPolicyOperator provides an implementation of few functions of
* PolicyOperator interface that other PolicyOperators can use.
*/
public abstract class AbstractPolicyOperator implements PolicyOperator {
protected List policyComponents = new ArrayList();
public AbstractPolicyOperator() {
}
public AbstractPolicyOperator(PolicyOperator parent) {
parent.addPolicyComponent(this);
}
public void addPolicyComponent(PolicyComponent component) {
if (component == null) {
throw new IllegalArgumentException("Component must not be null");
}
policyComponents.add(component);
}
public void addPolicyComponents(List components) {
policyComponents.addAll(components);
}
public List getPolicyComponents() {
return policyComponents;
}
public PolicyComponent getFirstPolicyComponent() {
if (policyComponents.isEmpty()) {
return null;
}
return policyComponents.get(0);
}
public boolean isEmpty() {
return policyComponents.isEmpty();
}
public boolean equal(PolicyComponent policyComponent) {
return PolicyComparator.compare(this, policyComponent);
}
protected static Policy normalize(Policy policy, PolicyRegistry reg, boolean deep) {
Policy result = new Policy(reg, policy.getNamespace());
String policyName = policy.getName();
if (policyName != null) {
result.setName(policyName);
}
String id = policy.getId();
if (id != null) {
result.setId(id);
}
result.addPolicyComponent(normalizeOperator(policy, policy, reg, deep));
return result;
}
private static PolicyComponent normalizeOperator(Policy policy,
PolicyOperator operator,
PolicyRegistry reg,
boolean deep) {
short type = operator.getType();
if (operator.isEmpty()) {
ExactlyOne exactlyOne = new ExactlyOne();
if (Constants.TYPE_EXACTLYONE != type) {
exactlyOne.addPolicyComponent(new All());
}
return exactlyOne;
}
List childComponentsList = new ArrayList();
for (PolicyComponent policyComponent : operator.getPolicyComponents()) {
if (policyComponent.getType() == Constants.TYPE_ASSERTION) {
if (deep) {
policyComponent = ((Assertion) policyComponent).normalize();
}
if (policyComponent.getType() == Constants.TYPE_POLICY) {
childComponentsList.add(((Policy) policyComponent).getFirstPolicyComponent());
} else {
ExactlyOne exactlyOne = new ExactlyOne();
All all = new All();
all.addPolicyComponent(policyComponent);
exactlyOne.addPolicyComponent(all);
childComponentsList.add(exactlyOne);
}
} else if (policyComponent.getType() == Constants.TYPE_POLICY_REF) {
String uri = ((PolicyReference) policyComponent).getURI();
policyComponent = reg == null ? null : reg.lookup(uri);
if (policyComponent == null && uri.charAt(0) == '#') {
String id = uri.substring(1);
policyComponent = reg == null ? null : reg.lookup(id);
if (policyComponent == null) {
for (PolicyComponent p : policy.getPolicyComponents()) {
if (p instanceof Policy && id.equals(((Policy)p).getId())) {
policyComponent = p;
}
}
}
}
if (policyComponent == null) {
throw new RuntimeException(uri + " can't be resolved");
}
All all = new All();
all.addPolicyComponents(((Policy) policyComponent).getPolicyComponents());
childComponentsList.add(AbstractPolicyOperator.normalizeOperator(policy, all, reg, deep));
} else if (policyComponent.getType() == Constants.TYPE_POLICY) {
All all = new All();
all.addPolicyComponents(((Policy) policyComponent).getPolicyComponents());
childComponentsList.add(AbstractPolicyOperator.normalizeOperator(policy, all, reg, deep));
} else {
childComponentsList.add(AbstractPolicyOperator
.normalizeOperator(policy,
(PolicyOperator)policyComponent, reg, deep));
}
}
return computeResultantComponent(childComponentsList, type);
}
private static PolicyComponent computeResultantComponent(List normalizedInnerComponets,
short componentType) {
ExactlyOne exactlyOne = new ExactlyOne();
if (componentType == Constants.TYPE_EXACTLYONE) {
for (PolicyComponent comp : normalizedInnerComponets) {
ExactlyOne innerExactlyOne = (ExactlyOne)comp;
exactlyOne.addPolicyComponents(innerExactlyOne.getPolicyComponents());
}
} else if ((componentType == Constants.TYPE_POLICY) || (componentType == Constants.TYPE_ALL)) {
// if the parent type is All then we have to get the cross product
if (normalizedInnerComponets.size() > 1) {
// then we have to get the cross product with each other to process all elements
Iterator iter = normalizedInnerComponets.iterator();
// first get the first element
exactlyOne = (ExactlyOne) iter.next();
// if this is empty, this is an not admissible policy and total result is equivalent to that
if (!exactlyOne.isEmpty()) {
ExactlyOne currentExactlyOne;
while (iter.hasNext()) {
currentExactlyOne = (ExactlyOne) iter.next();
if (currentExactlyOne.isEmpty()) {
// if this is empty, this is an not admissible policy and total
// result is equivalent to that
exactlyOne = currentExactlyOne;
break;
} else {
exactlyOne = getCrossProduct(exactlyOne, currentExactlyOne);
}
}
}
} else {
// i.e only one element exists in the list then we can safely
// return that element this is ok even if it is an empty element
exactlyOne = (ExactlyOne) normalizedInnerComponets.get(0);
}
}
return exactlyOne;
}
private static ExactlyOne getCrossProduct(ExactlyOne exactlyOne1, ExactlyOne exactlyOne2) {
ExactlyOne crossProduct = new ExactlyOne();
All crossProductAll;
All currentAll1;
All currentAll2;
for (PolicyComponent pc : exactlyOne1.getPolicyComponents()) {
currentAll1 = (All)pc;
for (PolicyComponent pc2 : exactlyOne2.getPolicyComponents()) {
currentAll2 = (All)pc2;
crossProductAll = new All();
crossProductAll.addPolicyComponents(currentAll1.getPolicyComponents());
crossProductAll.addPolicyComponents(currentAll2.getPolicyComponents());
crossProduct.addPolicyComponent(crossProductAll);
}
}
return crossProduct;
}
}
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