// Copyright 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.hivemind.impl;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.ErrorHandler;
import org.apache.hivemind.Occurances;
import org.apache.hivemind.ServiceImplementationFactory;
import org.apache.hivemind.internal.Module;
import org.apache.hivemind.internal.ServiceImplementationConstructor;
import org.apache.hivemind.internal.ServicePoint;
import org.apache.hivemind.schema.Schema;
/**
* Constructs a new service by invoking methods on
* another service (which implements the
* {@link org.apache.hivemind.ServiceImplementationFactory} interface.
*
* @author Howard Lewis Ship
*/
public final class InvokeFactoryServiceConstructor
extends BaseLocatable
implements ServiceImplementationConstructor
{
private String _factoryServiceId;
private ServicePoint _serviceExtensionPoint;
private Module _contributingModule;
/** List of {@link org.apache.hivemind.Element}, the raw XML parameters. */
private List _parameters;
/** The factory service to be invoked. */
private ServiceImplementationFactory _factory;
/** The parameters converted to objects as per the factory's parameter schema. */
private List _convertedParameters;
// TODO: Should this method be synchronized?
public Object constructCoreServiceImplementation()
{
Log serviceLog = _serviceExtensionPoint.getServiceLog();
if (_factory == null)
{
ServicePoint factoryPoint = _contributingModule.getServicePoint(_factoryServiceId);
Occurances expected = factoryPoint.getParametersCount();
_factory =
(ServiceImplementationFactory) factoryPoint.getService(
ServiceImplementationFactory.class);
Schema schema = factoryPoint.getParametersSchema();
// Note: it's kind of a toss up whether logging should occur using the
// id of the service being constructed, or of the factory being invoked.
// Here, we're using the constructed service ... with the intent being that
// users will enable debugging for the service (or search the logs for the service)
// if it fails to build properly.
ErrorHandler errorHandler = _contributingModule.getErrorHandler();
SchemaProcessorImpl processor =
new SchemaProcessorImpl(errorHandler, serviceLog, schema);
processor.process(_parameters, _contributingModule);
_convertedParameters = processor.getElements();
checkParameterCounts(errorHandler, serviceLog, expected);
}
try
{
return _factory.createCoreServiceImplementation(
_serviceExtensionPoint.getExtensionPointId(),
_serviceExtensionPoint.getServiceInterface(),
serviceLog,
_contributingModule,
_convertedParameters);
}
catch (Exception ex)
{
throw new ApplicationRuntimeException(ex.getMessage(), getLocation(), ex);
}
}
/**
* Checks that the number of parameter elements matches the expected count.
*/
private void checkParameterCounts(ErrorHandler handler, Log log, Occurances expected)
{
int actual = _convertedParameters.size();
if (expected.inRange(actual))
return;
String message = ImplMessages.wrongNumberOfParameters(_factoryServiceId, actual, expected);
handler.error(log, message, getLocation(), null);
}
public Module getContributingModule()
{
return _contributingModule;
}
public void setContributingModule(Module module)
{
_contributingModule = module;
}
public List getParameters()
{
return _parameters;
}
public ServicePoint getServiceExtensionPoint()
{
return _serviceExtensionPoint;
}
public void setParameters(List list)
{
_parameters = list;
}
public void setFactoryServiceId(String string)
{
_factoryServiceId = string;
}
public void setServiceExtensionPoint(ServicePoint point)
{
_serviceExtensionPoint = point;
}
}