/*
* Copyright 2001-2011 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.juddi.v3.client.mapping;
import java.net.BindException;
import java.net.URL;
import java.rmi.RemoteException;
import java.util.ArrayList;
import java.util.Properties;
import javax.xml.namespace.QName;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.juddi.api_v3.AccessPointType;
import org.apache.juddi.v3.client.ClassUtil;
import org.apache.juddi.v3.client.config.UDDIClerk;
import org.apache.juddi.v3.client.config.UDDIKeyConvention;
import org.apache.juddi.v3.client.subscription.SubscriptionCallbackListener;
import org.apache.juddi.v3.client.transport.TransportException;
import org.uddi.api_v3.AccessPoint;
import org.uddi.api_v3.BindingTemplate;
import org.uddi.api_v3.BindingTemplates;
import org.uddi.api_v3.BusinessService;
/**
* The ServiceLocator contacts the UDDI registry to lookup an Endpoint given a UDDI ServiceKey.<br>
* This class does NOT chase down WSDL, hosting redirectors or other binding references from
* access point useType values. See
* {@link org.apache.juddi.v3.client.config.UDDIClerk#getEndpoints UDDIClerk.getEndpoints}
* @see SubscriptionCallbackListener
* @author <a href="mailto:kstam@apache.org">Kurt T Stam</a>
*/
public class ServiceLocator {
private Log log = LogFactory.getLog(this.getClass());
private UDDIClerk clerk;
private Properties properties = new Properties();
private UDDIServiceCache serviceCache = null;
private String policy = null;
private SelectionPolicy selectionPolicy = null;
private URLLocalizer urlLocalizer = null;
/**
* Requirement in the config is a clerk with access credentials to the UDDI server
* you want the locator to do lookups to. When a live cache is used the clerk
* will register a callback into this UDDI server and the clerk will therefore need
* inquiry and publish access. The credentials can be set in the uddi-client.xml
* configuration file.
*
* @param clerk a UDDI Clerk with publish access to the UDDI Server.
* @throws ConfigurationException
*/
public ServiceLocator(UDDIClerk clerk) {
super();
this.clerk = clerk;
properties =clerk.getUDDINode().getProperties();
}
public ServiceLocator(UDDIClerk clerk, URLLocalizer urlLocalizer, Properties properties) throws ConfigurationException {
super();
this.clerk = clerk;
this.urlLocalizer = urlLocalizer;
this.properties = properties;
if (properties == null) properties = clerk.getUDDINode().getProperties();
}
public ServiceLocator withCache(URL baseCallbackURL) throws ConfigurationException {
if (serviceCache == null) {
serviceCache = initCache(baseCallbackURL);
}
return this;
}
/**
* A live cache will receive callbacks from the UDDI server in case there is an update to
* a service's bindings. All callbacks will clear the UDDIClientCache ensuring that subsequent
* lookups will contact the UDDI server for the latest binding information.
*
* The baseCallbackURL can be set to solve binding issue. If
*
* @param baseCallbackURL
* @return a service locator object
* @throws ConfigurationException
* @throws BindException
*/
public ServiceLocator withLiveCache(URL baseCallbackURL) throws ConfigurationException, BindException {
if (serviceCache == null) {
serviceCache = initCache(baseCallbackURL);
serviceCache.registerAsMBean();
}
if (! serviceCache.hasListener()) {
serviceCache.publishAndRegisterHttpCallbackEndpoint();
}
return this;
}
public UDDIServiceCache getUDDIServiceCache() {
return serviceCache;
}
/**
* The policy selection can be set as property "juddi.client.selection.policy"
* or it can be set programmatically using this method. A Policy is a class which
* implements the SelectionPolicy interface. Known implementations are
* org.apache.juddi.v3.client.mapping.PolicyLocalFirst and
* org.apache.juddi.v3.client.mapping.PolicyRoundRobin. If the policy is not
* set the default org.apache.juddi.v3.client.mapping.PolicyLocalFirst is used.
*
* @param policy - the desired policy.
* @return ServiceLocator
* @see org.apache.juddi.v3.client.mapping.PolicyLocalFirst
* @see org.apache.juddi.v3.client.mapping.PolicyRoundRobin
*/
public ServiceLocator setPolicy(String policy) {
this.policy = policy;
return this;
}
/**
* Returns the selection policy in use by this instance of the ServiceLocator.
*
* @return SelectionPolicy - the selection policy.
* @throws ConfigurationException
*/
public SelectionPolicy getPolicy() throws ConfigurationException {
try {
if (selectionPolicy==null) {
if (policy==null) {
//TODO move this constant to Property.class
policy = properties.getProperty("juddi.client.selection.policy", "org.apache.juddi.v3.client.mapping.PolicyLocalFirst");
}
@SuppressWarnings("unchecked")
Class<? extends SelectionPolicy> selectionPolicyClass = (Class<? extends SelectionPolicy>)
ClassUtil.forName(policy, this.getClass());
selectionPolicy = selectionPolicyClass.getConstructor(Properties.class).newInstance(properties);
}
return selectionPolicy;
} catch (Exception e) {
throw new ConfigurationException(e.getMessage(),e);
}
}
/**
* Creates a new UDDIServiceCache, which brings up a new WebService Endpoint. This
* EndPoint will be called by the UDDI server if any service changes. A callback
* will result in cleaning the cache.
*
* @param baseCallbackURL
* @throws ConfigurationException
*/
private UDDIServiceCache initCache(URL baseCallbackURL) throws ConfigurationException {
if (clerk==null) throw new ConfigurationException("The UDDIClerk is needed to use the UDDIServiceCache and is null");
if (urlLocalizer==null) urlLocalizer = new URLLocalizerDefaultImpl(baseCallbackURL);
try {
log.info("Creating a UDDICLientCache");
return new UDDIServiceCache(clerk, urlLocalizer, properties);
} catch (Exception e) {
throw new ConfigurationException(e.getMessage(),e);
}
}
/**
*
* @throws RemoteException
* @throws ConfigurationException
* @throws TransportException
*/
public void shutdown() throws RemoteException, ConfigurationException, TransportException {
serviceCache.shutdown();
}
/**
* Looks up the Endpoints for a Service. If the cache is in use it will try to
* obtain them from the cache. If no Endpoints are found, or if the cache is not
* in use, the clerk will do a lookup for this service. After Endpoints are found
* it will use a policy to pick one Endpoint to return. Returns null if no endpoints
* are found.
*
* @param serviceKey
* @return endpoint
* @throws RemoteException
* @throws ConfigurationException
* @throws TransportException
*/
public String lookupEndpoint(String serviceKey) throws RemoteException, ConfigurationException, TransportException {
Topology topology = null;
if (serviceCache==null) { //nocache in use
topology = lookupEndpointInUDDI(serviceKey);
} else { //with cache
//try to get it from the cache first
topology = serviceCache.lookupService(serviceKey);
if (topology==null) { //not found in the cache
topology = lookupEndpointInUDDI(serviceKey);
}
}
if (topology!=null && topology.getEprs().size() > 0) {
String epr = getPolicy().select(topology);
return epr;
} else {
return null;
}
}
/**
* Looks up the Endpoints for a Service. If the cache is in use it will try to
* obtain them from the cache. If no Endpoints are found, or if the cache is not
* in use, the clerk will do a lookup for this service. After Endpoints are found
* it will use a policy to pick one Endpoint to return. Returns null if no endpoints
* are found.
*
* @param serviceQName
* @param portName
* @return Returns null if no endpoints
* are found.
* @throws TransportException
* @throws ConfigurationException
* @throws RemoteException
*/
public String lookupEndpoint(QName serviceQName, String portName) throws RemoteException, ConfigurationException, TransportException {
String serviceKey = UDDIKeyConvention.getServiceKey(properties, serviceQName.getLocalPart());
return lookupEndpoint(serviceKey);
}
private Topology lookupEndpointInUDDI(String serviceKey) throws RemoteException, ConfigurationException, TransportException {
Topology topology = null;
BusinessService service = clerk.getServiceDetail(serviceKey);
if (service==null) {
log.warn("No Service with key " + serviceKey + " was found in the registry.");
//TODO find service by tModel
}
if (service!=null && service.getBindingTemplates()!=null && service.getBindingTemplates().getBindingTemplate() != null) {
ArrayList<String> eprs = new ArrayList<String>();
BindingTemplates bindingTemplates = service.getBindingTemplates();
if (bindingTemplates==null) {
log.warn("Found service " + service.getName().get(0).getValue()
+ " with serviceKey '" + serviceKey + "'"
+ " but no EPRs");
} else {
log.debug("Found service " + service.getName().get(0).getValue()
+ " with serviceKey '" + serviceKey + "'"
+ " and " + bindingTemplates.getBindingTemplate().size() + " EPRs");
//Loop over all bindingTemplates found and get the endpoints.
for (BindingTemplate bindingTemplate : bindingTemplates.getBindingTemplate()) {
AccessPoint accessPoint = bindingTemplate.getAccessPoint();
if (AccessPointType.END_POINT.toString().equals(accessPoint.getUseType())) {
String url = accessPoint.getValue();
log.debug("epr= " + url);
eprs.add(url);
}
}
if (eprs.size()>0) {
topology = new Topology(eprs);
}
}
}
if (serviceCache!=null && topology!=null) { //add to cache
serviceCache.addService(serviceKey, topology);
}
return topology;
}
}