Selector.java

/*
 * Copyright to the original author or authors.
 *
 * 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.rioproject.monitor.service.selectors;

import org.rioproject.monitor.service.InstantiatorResource;
import org.rioproject.monitor.service.ProvisionException;
import org.rioproject.monitor.service.ProvisionRequest;
import org.rioproject.impl.service.ServiceResource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Select a {@link org.rioproject.impl.service.ServiceResource} based on a {@link org.rioproject.opstring.ServiceElement}
 */
public class Selector {
    private static final Logger logger = LoggerFactory.getLogger(Selector.class);

    /**
     * Get a ServiceBeanInstantiator that meets the operational requirements of a
     * ServiceElement
     *
     * @param request  The ProvisionRequest
     * @param selector A selector
     * @return A ServiceResource that contains an InstantiatorResource that meets the operational criteria of the
     * ServiceElement
     */
    public static ServiceResource acquireServiceResource(final ProvisionRequest request,
                                                         final ServiceResourceSelector selector) {
        ServiceResource resource = null;
        try {
            if (request.getRequestedUuid() != null) {
                resource = selector.getServiceResource(request, request.getRequestedUuid(), true);
                /* If the returned resource is null, then try to get any resource */
                if (resource == null) {
                    resource = selector.getServiceResource(request);
                }

            } else if (request.getExcludeUuid() != null) {
                resource = selector.getServiceResource(request, request.getExcludeUuid(), false);
            } else {
                resource = selector.getServiceResource(request);
            }

            if (resource != null) {
                InstantiatorResource ir = (InstantiatorResource) resource.getResource();
                ir.incrementProvisionCounter(request.getServiceElement());
            }
        } catch (ProvisionException e) {
            if (e.isUninstantiable()) {
                request.setType(ProvisionRequest.Type.UNINSTANTIABLE);
                request.getListener().uninstantiable(request);
            }
        } catch (Exception e) {
            logger.warn("Getting ServiceResource", e);
        }
        return resource;
    }

}