/*
 * Copyright (c) 2014, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.client.spi;

import javax.ws.rs.client.Client;
import javax.ws.rs.core.Configuration;

Caching connector provider.
This utility provider can be used to serve as a lazily initialized provider of the same connector instance.
 Note however that the connector instance will be configured using the runtime configuration of the first client instance that has invoked the getConnector(Client, Configuration) method. Client and Configuration instance passed to subsequent getConnector(...) invocations will be ignored. As such, this connector provider should not be shared among client instances that have significantly different connector-specific settings. 
Author:
Marek Potociar
Since:
2.10/**
 * Caching connector provider.
 *
 * This utility provider can be used to serve as a lazily initialized provider of the same connector instance.
 * <p>
 * Note however that the connector instance will be configured using the runtime configuration of the first client instance that
 * has invoked the {@link #getConnector(javax.ws.rs.client.Client, javax.ws.rs.core.Configuration)} method.
 * {@link javax.ws.rs.client.Client} and {@link javax.ws.rs.core.Configuration} instance passed to subsequent
 * {@code getConnector(...)} invocations will be ignored. As such, this connector provider should not be shared among client
 * instances that have significantly different connector-specific settings.
 * </p>
 *
 * @author Marek Potociar
 * @since 2.10
 */
public class CachingConnectorProvider implements ConnectorProvider {

    private final ConnectorProvider delegate;
    private Connector connector;


    
Create the caching connector provider.
Params:
delegate – delegate connector provider that will be used to initialize and create the connector instance which
                will be subsequently cached and reused./**
     * Create the caching connector provider.
     *
     * @param delegate delegate connector provider that will be used to initialize and create the connector instance which
     *                 will be subsequently cached and reused.
     */
    public CachingConnectorProvider(final ConnectorProvider delegate) {
        this.delegate = delegate;
    }

    @Override
    public synchronized Connector getConnector(Client client, Configuration runtimeConfig) {
        if (connector == null) {
            connector = delegate.getConnector(client, runtimeConfig);
        }
        return connector;
    }
}