/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* 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.tuscany.sca.policy.xml;
import static org.apache.tuscany.sca.policy.xml.PolicyConstants.SCA11_NS;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.StringTokenizer;
import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import org.apache.tuscany.sca.common.xml.xpath.XPathHelper;
import org.apache.tuscany.sca.contribution.processor.BaseStAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
import org.apache.tuscany.sca.contribution.processor.ProcessorContext;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.FactoryExtensionPoint;
import org.apache.tuscany.sca.monitor.Monitor;
import org.apache.tuscany.sca.monitor.Problem;
import org.apache.tuscany.sca.monitor.Problem.Severity;
import org.apache.tuscany.sca.policy.ExternalAttachment;
import org.apache.tuscany.sca.policy.Intent;
import org.apache.tuscany.sca.policy.PolicyFactory;
import org.apache.tuscany.sca.policy.PolicySet;
/**
* Processor for handling XML models of ExternalAttachment definitions
*
* @version $Rev: 961010 $ $Date: 2010-07-06 13:34:54 -0700 (Tue, 06 Jul 2010) $
*/
public class ExternalAttachmentProcessor extends BaseStAXArtifactProcessor
implements StAXArtifactProcessor<ExternalAttachment>, PolicyConstants {
private PolicyFactory policyFactory;
private XPathHelper xpathHelper;
public ExternalAttachmentProcessor(ExtensionPointRegistry registry) {
FactoryExtensionPoint factories = registry.getExtensionPoint(FactoryExtensionPoint.class);
this.policyFactory = factories.getFactory(PolicyFactory.class);
this.xpathHelper = XPathHelper.getInstance(registry);
}
public Class<ExternalAttachment> getModelType() {
return ExternalAttachment.class;
}
public void resolve(ExternalAttachment attachment, ModelResolver resolver,
ProcessorContext context) throws ContributionResolveException {
if (attachment != null && attachment.isUnresolved()) {
resolveIntents(attachment, resolver, context);
resolvePolicySets(attachment, resolver, context);
attachment.setUnresolved(false);
}
}
private void resolvePolicySets(ExternalAttachment attachment,
ModelResolver resolver, ProcessorContext context) {
List<PolicySet> referredPolicySets = new ArrayList<PolicySet>();
for (PolicySet referredPolicySet : attachment.getPolicySets()) {
if (referredPolicySet.isUnresolved()) {
PolicySet resolved = resolver.resolveModel(PolicySet.class, referredPolicySet, context);
if (!resolved.isUnresolved() || resolved != referredPolicySet) {
referredPolicySets.add(resolved);
} else {
error(context.getMonitor(), "ReferredPolicySetNotFound", attachment, referredPolicySet, attachment);
return;
}
} else {
referredPolicySets.add(referredPolicySet);
}
}
attachment.getPolicySets().clear();
attachment.getPolicySets().addAll(referredPolicySets);
}
private void resolveIntents(ExternalAttachment attachment,
ModelResolver resolver, ProcessorContext context) {
if (attachment != null) {
//resolve all provided intents
List<Intent> providedIntents = new ArrayList<Intent>();
for (Intent providedIntent : attachment.getIntents()) {
if (providedIntent.isUnresolved()) {
Intent resolved = resolver.resolveModel(Intent.class, providedIntent, context);
if (!resolved.isUnresolved() || resolved != providedIntent) {
providedIntents.add(resolved);
} else {
error(context.getMonitor(), "ProvidedIntentNotFound", attachment, providedIntent, attachment);
return;
}
} else {
providedIntents.add(providedIntent);
}
}
attachment.getIntents().clear();
attachment.getIntents().addAll(providedIntents);
}
}
public QName getArtifactType() {
return EXTERNAL_ATTACHMENT_QNAME;
}
public ExternalAttachment read(XMLStreamReader reader, ProcessorContext context)
throws ContributionReadException, XMLStreamException {
ExternalAttachment attachment = policyFactory.createExternalAttachment();
readPolicySets(attachment, reader);
readIntents(attachment, reader, context);
readAttachTo(attachment, reader, context);
return attachment;
}
private void readIntents(ExternalAttachment attachment,
XMLStreamReader reader, ProcessorContext context) {
String value = reader.getAttributeValue(null, INTENTS);
if (value != null) {
List<Intent> intents = attachment.getIntents();
for (StringTokenizer tokens = new StringTokenizer(value); tokens.hasMoreTokens();) {
QName qname = getQNameValue(reader, tokens.nextToken());
Intent intent = policyFactory.createIntent();
intent.setName(qname);
intents.add(intent);
}
}
}
private void readAttachTo(ExternalAttachment attachment,
XMLStreamReader reader, ProcessorContext context) {
Monitor monitor = context.getMonitor();
String attachTo = reader.getAttributeValue(null, ATTACH_TO);
if ( attachTo != null ) {
try {
XPath path = xpathHelper.newXPath();
NamespaceContext nsContext = xpathHelper.getNamespaceContext(attachTo, reader.getNamespaceContext());
path.setXPathFunctionResolver(new PolicyXPathFunctionResolver(nsContext));
attachTo = PolicyXPathFunction.normalize(attachTo,getSCAPrefix(nsContext));
XPathExpression expression = xpathHelper.compile(path, nsContext, attachTo);
attachment.setAttachTo(attachTo);
attachment.setAttachToXPathExpression(expression);
} catch (XPathExpressionException e) {
ContributionReadException ce = new ContributionReadException(e);
error(monitor, "ContributionReadException", attachment, ce);
}
}
}
private String getSCAPrefix(NamespaceContext nsContext) {
Iterator<String> iter = nsContext.getPrefixes(SCA11_NS);
while (iter.hasNext()) {
String prefix = iter.next();
if (!prefix.equals(XMLConstants.DEFAULT_NS_PREFIX)) {
return prefix;
}
}
return "__sca";
}
/**
* Reads policy sets associated with an external attachment element.
* @param subject
* @param operation
* @param reader
*/
private void readPolicySets(ExternalAttachment attachment, XMLStreamReader reader) {
String value = reader.getAttributeValue(null, POLICY_SETS);
if (value != null) {
List<PolicySet> policySets = attachment.getPolicySets();
for (StringTokenizer tokens = new StringTokenizer(value); tokens.hasMoreTokens();) {
QName qname = getQNameValue(reader, tokens.nextToken());
PolicySet policySet = policyFactory.createPolicySet();
policySet.setName(qname);
policySets.add(policySet);
}
}
}
public void write(ExternalAttachment attachment, XMLStreamWriter writer,
ProcessorContext context) throws ContributionWriteException,
XMLStreamException {
writePolicySets(attachment, writer, context);
writeIntents(attachment, writer, context);
writeAttachTo(attachment, writer, context);
}
private void writeAttachTo(ExternalAttachment attachment,
XMLStreamWriter writer, ProcessorContext context) throws XMLStreamException {
if ( attachment.getAttachTo() != null ) {
writer.writeAttribute(PolicyConstants.ATTACH_TO, attachment.getAttachTo());
}
}
private void writeIntents(ExternalAttachment attachment,
XMLStreamWriter writer, ProcessorContext context) throws XMLStreamException {
if (!attachment.getIntents().isEmpty()) {
StringBuffer sb = new StringBuffer();
for (Intent intent : attachment.getIntents()) {
sb.append(getQualifiedName(intent.getName(), writer));
sb.append(" ");
}
// Remove the last space
sb.deleteCharAt(sb.length() - 1);
writer.writeAttribute(PolicyConstants.INTENTS, sb.toString());
}
}
private void writePolicySets(ExternalAttachment attachment,
XMLStreamWriter writer, ProcessorContext context) throws XMLStreamException {
if ( !attachment.getPolicySets().isEmpty()) {
StringBuffer sb = new StringBuffer();
for (PolicySet ps : attachment.getPolicySets()) {
sb.append(getQualifiedName(ps.getName(), writer));
sb.append(" ");
}
// Remove the last space
sb.deleteCharAt(sb.length() - 1);
writer.writeAttribute(PolicyConstants.POLICY_SETS, sb.toString());
}
}
private String getQualifiedName(QName name, XMLStreamWriter writer) throws XMLStreamException {
String local = name.getLocalPart();
String prefix = writer.getPrefix(name.getNamespaceURI());
if (prefix != null && prefix.length() > 0) {
return prefix + ':' + local;
} else {
return local;
}
}
/**
* Report a error.
*
* @param problems
* @param message
* @param model
*/
private void error(Monitor monitor, String message, Object model, Object... messageParameters) {
if (monitor != null) {
Problem problem =
monitor.createProblem(this.getClass().getName(),
Messages.RESOURCE_BUNDLE,
Severity.ERROR,
model,
message,
(Object[])messageParameters);
monitor.problem(problem);
}
}
}