com.msopentech.odatajclient.proxy.api.EntityContainerFactory.java Source code

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Here is the source code for com.msopentech.odatajclient.proxy.api.EntityContainerFactory.java

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/**
 * 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 com.msopentech.odatajclient.proxy.api;

import com.msopentech.odatajclient.engine.client.Configuration;
import com.msopentech.odatajclient.engine.client.ODataClientFactory;
import com.msopentech.odatajclient.engine.client.ODataV3Client;
import com.msopentech.odatajclient.engine.communication.request.retrieve.ODataV3MetadataRequest;
import com.msopentech.odatajclient.proxy.api.context.Context;
import com.msopentech.odatajclient.engine.communication.response.ODataRetrieveResponse;
import com.msopentech.odatajclient.engine.metadata.EdmV3Metadata;
import com.msopentech.odatajclient.engine.uri.filter.FilterFactory;
import com.msopentech.odatajclient.proxy.api.impl.EntityContainerInvocationHandler;
import java.lang.reflect.Proxy;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.lang3.StringUtils;

/**
 * Entry point for ODataJClient proxy mode, gives access to entity container instances.
 */
public class EntityContainerFactory {

    private static final Object MONITOR = new Object();

    private static Context context = null;

    private static final Map<String, EntityContainerFactory> FACTORY_PER_SERVICEROOT = new ConcurrentHashMap<String, EntityContainerFactory>();

    private static final Map<Class<?>, Object> ENTITY_CONTAINERS = new ConcurrentHashMap<Class<?>, Object>();

    private final ODataV3Client client;

    private final String serviceRoot;

    private EdmV3Metadata metadata;

    public static Context getContext() {
        synchronized (MONITOR) {
            if (context == null) {
                context = new Context();
            }
        }

        return context;
    }

    private static EntityContainerFactory getInstance(final ODataV3Client client, final String serviceRoot) {
        if (!FACTORY_PER_SERVICEROOT.containsKey(serviceRoot)) {
            final EntityContainerFactory instance = new EntityContainerFactory(client, serviceRoot);
            FACTORY_PER_SERVICEROOT.put(serviceRoot, instance);
        }
        return FACTORY_PER_SERVICEROOT.get(serviceRoot);
    }

    public static EntityContainerFactory getV3Instance(final String serviceRoot) {
        return getInstance(ODataClientFactory.getV3(), serviceRoot);
    }

    private EntityContainerFactory(final ODataV3Client client, final String serviceRoot) {
        this.client = client;
        this.serviceRoot = serviceRoot;
    }

    public Configuration getConfiguration() {
        return client.getConfiguration();
    }

    public FilterFactory getFilterFactory() {
        return client.getFilterFactory();
    }

    public String getServiceRoot() {
        return serviceRoot;
    }

    public EdmV3Metadata getMetadata() {
        synchronized (this) {
            if (metadata == null) {
                final ODataV3MetadataRequest req = client.getRetrieveRequestFactory()
                        .getMetadataRequest(serviceRoot);
                final ODataRetrieveResponse<EdmV3Metadata> res = req.execute();
                metadata = res.getBody();
                if (metadata == null) {
                    throw new IllegalStateException("No metadata found at URI '" + serviceRoot + "'");
                }
            }
        }

        return metadata;
    }

    /**
     * Return an initialized concrete implementation of the passed EntityContainer interface.
     *
     * @param <T> interface annotated as EntityContainer
     * @param reference class object of the EntityContainer annotated interface
     * @return an initialized concrete implementation of the passed reference
     * @throws IllegalStateException if <tt>serviceRoot</tt> was not set
     * @throws IllegalArgumentException if the passed reference is not an interface annotated as EntityContainer
     * @see com.msopentech.odatajclient.proxy.api.annotations.EntityContainer
     */
    @SuppressWarnings("unchecked")
    public <T> T getEntityContainer(final Class<T> reference)
            throws IllegalStateException, IllegalArgumentException {
        if (StringUtils.isBlank(serviceRoot)) {
            throw new IllegalStateException("serviceRoot was not set");
        }

        if (!ENTITY_CONTAINERS.containsKey(reference)) {
            final Object entityContainer = Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
                    new Class<?>[] { reference },
                    EntityContainerInvocationHandler.getInstance(client, reference, this));
            ENTITY_CONTAINERS.put(reference, entityContainer);
        }
        return (T) ENTITY_CONTAINERS.get(reference);
    }
}