factory for getting ES client

TransportClientFactory.java

package com.foo.search;

import org.apache.log4j.Logger;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.collect.ImmutableList;
import org.elasticsearch.common.settings.ImmutableSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;

import java.util.Map;

public class TransportClientFactory {

    private static final Logger log = Logger.getLogger(TransportClientFactory.class);

    private Map<String, String> settings;
    private String clientTransportHost;
    private Integer clientTransportPort;
    private boolean disabled = false;

    public TransportClientFactory(Map<String, String> settings,
                                  String clientTransportHost,
                                  Integer clientTransportPort,
                                  boolean disabled) {
        this.settings = settings;
        this.clientTransportHost = clientTransportHost;
        this.clientTransportPort = clientTransportPort;
        this.disabled = disabled;
    }

    public TransportClient getClient() throws ElasticSearchUnavailableException {
        
        if (this.disabled) {
            throw new ElasticSearchUnavailableException("ES is disabled. Check 'es.disable' property");
        }
        
        log.info("getting client");
        Settings s = ImmutableSettings.settingsBuilder()
                .put(this.settings)
                .build();
        TransportClient client = new TransportClient(s);
        client.addTransportAddress(new InetSocketTransportAddress(
                this.clientTransportHost,
                this.clientTransportPort)
        );

        verifyConnection(client);
        
        return client;
    }

    private void verifyConnection(TransportClient client) {
        ImmutableList<DiscoveryNode> nodes = client.connectedNodes();
        if (nodes.isEmpty()) {
            throw new ElasticSearchUnavailableException("No nodes available. Verify ES is running!");
        } else {
            log.info("connected to nodes: " + nodes.toString());
        }
    }
}