ProxiedHttpConnectionFactory.java

package org.wikidata.query.rdf.blazegraph;

import java.util.Arrays;
import java.util.Collections;
import java.util.stream.Collectors;

import javax.annotation.Nullable;

import org.eclipse.jetty.client.HttpClient;
import org.eclipse.jetty.client.HttpProxy;
import org.eclipse.jetty.client.ProxyConfiguration;
import org.eclipse.jetty.http.HttpField;
import org.eclipse.jetty.http.HttpHeader;

import com.bigdata.rdf.sail.webapp.client.DefaultHttpClientFactory;
import com.bigdata.rdf.sail.webapp.client.IHttpClientFactory;
import com.google.common.annotations.VisibleForTesting;

/**
 * Http client factory that knows about proxy settings.
 */
public class ProxiedHttpConnectionFactory implements IHttpClientFactory {

    /**
     * Default factory instance.
     */
    private final DefaultHttpClientFactory defaultFactory;

    /**
     * Configuration name for proxy host.
     */
    private static final String HTTP_PROXY = "http.proxyHost";
    /**
     * Configuration name for proxy port.
     */
    private static final String HTTP_PROXY_PORT = "http.proxyPort";

    /** Configuration of excluded hosts. */
    private static final String HTTP_PROXY_EXCLUDED_HOSTS = "http.proxyExcludedHosts";
    private static final String HTTP_PROXY_CLIENT_IDLE_TIMEOUT = "http.proxyIdleTimeout";
    private static final String HTTP_PROXY_CLIENT_IDLE_TIMEOUT_DEFAULT = "300000";

    /**
     * Configuration name for User agent.
     */
    private static final String HTTP_USER_AGENT = "http.userAgent";
    public ProxiedHttpConnectionFactory() {
        defaultFactory = new DefaultHttpClientFactory();
    }

    @Override
    public HttpClient newInstance() {
        final HttpClient client = defaultFactory.newInstance();

        if (System.getProperty(HTTP_PROXY) != null
                && System.getProperty(HTTP_PROXY_PORT) != null) {
            final ProxyConfiguration proxyConfig = client.getProxyConfiguration();
            final HttpProxy proxy = new HttpProxy(
                    System.getProperty(HTTP_PROXY),
                    Integer.parseInt(System.getProperty(HTTP_PROXY_PORT)));
            proxy.getExcludedAddresses().add("localhost");
            proxy.getExcludedAddresses().add("127.0.0.1");
            getListOfExcludedHosts(System.getProperty(HTTP_PROXY_EXCLUDED_HOSTS))
                    .forEach(h -> proxy.getExcludedAddresses().add(h));
            proxyConfig.getProxies().add(proxy);
        }
        final String userAgent = System.getProperty(HTTP_USER_AGENT);
        if (userAgent != null) {
            client.setUserAgentField(new HttpField(HttpHeader.USER_AGENT, userAgent));
        }
        client.setIdleTimeout(Integer.parseInt(System.getProperty(HTTP_PROXY_CLIENT_IDLE_TIMEOUT, HTTP_PROXY_CLIENT_IDLE_TIMEOUT_DEFAULT)));

        return client;
    }

    @VisibleForTesting
    public static Iterable<String> getListOfExcludedHosts(@Nullable String excludedHostsConfig) {
        if (excludedHostsConfig == null) {
            return Collections.emptyList();
        }
        return Arrays.stream(excludedHostsConfig.split(","))
                .map(String::trim)
                .filter(h -> !h.isEmpty())
                .collect(Collectors.toList());
    }

}