EDIT

/**

* Copyright (C) 2020 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.service;

import java.io.IOException;

import java.net.URI;

import java.time.LocalDateTime;

import java.time.format.DateTimeFormatter;

import org.apache.http.Header;

import org.apache.http.HttpResponse;

import org.apache.http.client.HttpClient;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.config.Registry;

import org.apache.http.config.RegistryBuilder;

import org.apache.http.conn.socket.ConnectionSocketFactory;

import org.apache.http.conn.socket.PlainConnectionSocketFactory;

import org.apache.http.conn.ssl.SSLConnectionSocketFactory;

import org.apache.http.impl.NoConnectionReuseStrategy;

import org.apache.http.impl.client.HttpClientBuilder;

import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;

import org.springframework.remoting.httpinvoker.HttpComponentsHttpInvokerRequestExecutor;

import org.springframework.remoting.httpinvoker.HttpInvokerClientConfiguration;

import eu.etaxonomy.taxeditor.remoting.RemoteExecutionTimestampsUtil;

/**

 * HttpInvokerRequestExecutor which extends the spring

 * {@link HttpComponentsHttpInvokerRequestExecutor} by two functionalities:

 *

 * <ol>

 * <li>Records time stamps when sending the request and when receiving the response.</li>

 * <li>Allows custom configuration of the {@link PoolingHttpClientConnectionManager}

 * (see <a href="https://dev.e-taxonomy.eu/redmine/issues/8812">https://dev.e-taxonomy.eu/redmine/issues/8812</a>).

 * </ol>

 *

 * @author a.kohlbecker

 * @since Jan 17, 2020

 */

public class TimestampingHttpInvokerRequestExecutor extends HttpComponentsHttpInvokerRequestExecutor {

    private static final int DEFAULT_MAX_TOTAL_CONNECTIONS = 100;

    private static final int DEFAULT_MAX_CONNECTIONS_PER_ROUTE = 5;

    /**

     * Default in PoolingHttpClientConnectionManager is 2000 milliseconds.

     *

     * see https://stackoverflow.com/questions/10558791/apache-httpclient-interim-error-nohttpresponseexception

     */

    private static final int VALIDATE_AFTER_INACTIVITY = 2000;

    public TimestampingHttpInvokerRequestExecutor() {

        super(createDefaultHttpClient());

    }

    @Override

    protected HttpResponse executeHttpPost(HttpInvokerClientConfiguration config, HttpClient httpClient,

            HttpPost httpPost) throws IOException {

        setExecutionRequestClientTimestamp(httpPost.getURI());

        HttpResponse response = super.executeHttpPost(config, httpClient, httpPost);

        setExecutionResponseHttpHeaderTimestamp(response);

        return response;

    }

    private void setExecutionRequestClientTimestamp(URI requestURI){

        LocalDateTime date = LocalDateTime.now();

        String dateTimeStr = date.format(DateTimeFormatter.ISO_DATE_TIME);

        RemoteExecutionTimestampsUtil.setLastRequestClientTime(dateTimeStr);

        if(requestURI != null){

            RemoteExecutionTimestampsUtil.setLastService(requestURI.toString());

        }

    }

    private void setExecutionResponseHttpHeaderTimestamp(HttpResponse respone){

        Header dateHeader = respone.getFirstHeader("Date");

        if(dateHeader != null){

            RemoteExecutionTimestampsUtil.setLastResponseHttpHeaderTime(dateHeader.getValue());

        }

    }

    private static HttpClient createDefaultHttpClient() {

        Registry<ConnectionSocketFactory> schemeRegistry = RegistryBuilder.<ConnectionSocketFactory>create()

                .register("http", PlainConnectionSocketFactory.getSocketFactory())

                .register("https", SSLConnectionSocketFactory.getSocketFactory())

                .build();

        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(schemeRegistry);

        connectionManager.setMaxTotal(DEFAULT_MAX_TOTAL_CONNECTIONS);

        connectionManager.setDefaultMaxPerRoute(DEFAULT_MAX_CONNECTIONS_PER_ROUTE);

        connectionManager.setValidateAfterInactivity(VALIDATE_AFTER_INACTIVITY);

        return HttpClientBuilder.create()

                .setConnectionManager(connectionManager)

                .setConnectionReuseStrategy(new NoConnectionReuseStrategy()) // see #8812

                .build();

    }

}