source: gs3-extensions/solr/trunk/src/src/java/org/greenstone/gsdl3/service/SolrSearch.java

package org.greenstone.gsdl3.service;

// Greenstone classes
import org.greenstone.gsdl3.util.*;
import org.greenstone.util.GlobalProperties;
import org.greenstone.util.ProtocolPortProperties;

// XML classes
import org.w3c.dom.Element; 
import org.w3c.dom.Document;
import org.w3c.dom.NodeList; 

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Properties;

import org.apache.log4j.Logger;
import org.apache.solr.client.solrj.SolrQuery;
import org.apache.solr.client.solrj.SolrServer;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.impl.HttpSolrServer;
import org.apache.solr.client.solrj.response.QueryResponse;
import org.apache.solr.common.SolrDocument;
import org.apache.solr.common.SolrDocumentList;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.servlet.SolrRequestParsers;


public class SolrSearch extends LuceneSearch {

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.SolrSearch.class.getName());

    protected String solr_servlet_base_url;
    protected HashMap<String, SolrServer> solr_server;

    public SolrSearch()
    {
    solr_server = new HashMap<String, SolrServer>();    

    // Create the solr servlet url on GS3's tomcat. By default it's "http://localhost:8383/solr"
    // Don't do this in configure(), since the tomcat url will remain unchanged while tomcat is running
    try {
        Properties globalProperties = new Properties();
        globalProperties.load(Class.forName("org.greenstone.util.GlobalProperties").getClassLoader().getResourceAsStream("global.properties"));

        /*
        String host = globalProperties.getProperty("tomcat.server", "localhost");
        //String port = globalProperties.getProperty("tomcat.port.http", "8383");
        //String protocol = globalProperties.getProperty("server.protocol", "http");
        ProtocolPortProperties protocolPortProps = new ProtocolPortProperties(globalProperties); // can throw an Exception      
        String protocol = protocolPortProps.getProtocol();
        String port = protocolPortProps.getPort();
        String solrContext = globalProperties.getProperty("solr.context", "solr");
        
        String portStr = port.equals("80") ? "" : ":"+port;
        solr_servlet_base_url = protocol+"://"+host+portStr+"/"+solrContext;
        */

        // The solr servlet is only accessible locally (from "localhost",  specifically 127.0.0.1).
        // for security reasons, as we don't want non librarian users
        // to go to the solr servlet and delete solr cores or something.
        // The security Valve element in the tomcat solr.xml context file restricts
        // access to 127.0.0.1, but here we ensure that the solr URL is the local http one
        // and not any https with domain name and https port.
        // Note that we use 127.0.0.1 instead of literally "localhost" since localhost is unsafe
        ProtocolPortProperties protocolPortProps = new ProtocolPortProperties(globalProperties); // can throw an Exception
        String solrContext = globalProperties.getProperty("solr.context", "solr");
        solr_servlet_base_url = protocolPortProps.getLocalHttpBaseAddress()+"/"+solrContext;
    } catch(Exception e) {
        logger.error("Error reading greenstone's tomcat solr server properties from global.properties", e);
    }
    }
    

    // Overriding the cleanUp() method here, so as to parallel the structure of GS2SolrSearch 
    // which also calls shutdown() on its CoreContainer object in GS2SolrSearch.cleanUp().
    // However, this class has not yet been tested, so it's not certain that this method is 
    // required here.
    // Adjusted  to bring it up to speed with changes in GS2SolrSearch (for activate.pl) - not yet tested
    public void cleanUp() {
    super.cleanUp();
    
    // clear the map keeping track of the SolrServers in this collection
    solr_server.clear();
    }

    
    // adjusted configure to bring it up to speed with changes in GS2SolrSearch (for activate.pl) - not yet tested
    public boolean configure(Element info, Element extra_info) {
    boolean success = super.configure(info, extra_info);
    
    // clear the map of solr cores for this collection added to the map upon querying
    solr_server.clear();
    
    if(!success) {
        return false;
    }
    
    if(solr_servlet_base_url == null) {
        logger.error("Unable to configure SolrSearch - solr_servlet_base_url is null because of issues with port/protocol in global.properties");
        return false;
    }
    // initialize required number of SolrCores based on values
    // in 'index_ids' that are set by LuceneSearch::configure()

    String core_name_prefix = getCollectionCoreNamePrefix();

    for (int i=0; i<index_ids.size(); i++) {

        String idx_name = (String)index_ids.get(i);
        String core_name = core_name_prefix + "-" + idx_name;

        SolrServer solr_core = new HttpSolrServer(this.solr_servlet_base_url+"/"+core_name);
        solr_server.put(core_name,solr_core);
    }
    

    return success;
    }
    
    protected void getIndexData(ArrayList index_ids, ArrayList index_names, String lang) 
    {
    }

    /** Process a text query - implemented by concrete subclasses */
    protected Element processTextQuery(Element request) {

      Document result_doc = XMLConverter.newDOM();
    Element result = result_doc.createElement(GSXML.RESPONSE_ELEM);
    Element doc_node_list = result_doc.createElement(GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER);
    Element metadata_list = result_doc.createElement(GSXML.METADATA_ELEM+GSXML.LIST_MODIFIER);
    initResultElement(result,doc_node_list,metadata_list);

    if (!hasParamList(request,metadata_list)) {
        return result;
    }

    Element param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    if (!hasQueryString(param_list,metadata_list)) {
        return result;
    }

    HashMap params = GSXML.extractParams(param_list, false);
    String query_string = (String) params.get(QUERY_PARAM);


    // Get the index
    String index = (String) params.get(INDEX_PARAM);
    if (index == null || index.equals("")) {
        index = this.default_index; // assume the default
    }

        try {
        
        // Use SolrQuery with HttpSolrServer instead of ModifiableSolrParams, 
        // see http://stackoverflow.com/questions/13944567/querying-solr-server-using-solrj     
        SolrQuery solrParams = new SolrQuery(query_string); // initialised with q url-parameter
        //solrparams.setRequestHandler("/select"); // default. Or try "select"

        ///solrParams.set("start", start);
        ///solrParams.set("rows", nbDocuments);


        String core_name = getCollectionCoreNamePrefix() + "-" + index;

        // http://stackoverflow.com/questions/17026530/accessing-a-cores-default-handler-through-solrj-using-setquerytype
        // default request handler is /select, see http://wiki.apache.org/solr/CoreQueryParameters
        SolrServer solr_core = solr_server.get(core_name);
        QueryResponse solrResponse = solr_core.query(solrParams);

        SolrDocumentList hits = solrResponse.getResults();

        if (hits != null) {
        // or should this be docs.getNumFound() ??
        GSXML.addMetadata(metadata_list, "numDocsMatched", ""+hits.size());

        System.err.println(hits.getNumFound() + " documents found, "
                   + hits.size() + " returned : ");

        for (int i = 0; i < hits.size(); i++) {
            SolrDocument solr_doc = hits.get(i);

            String node_id = (String)solr_doc.get("docOID");
            Element node = result_doc.createElement(GSXML.DOC_NODE_ELEM);
            node.setAttribute(GSXML.NODE_ID_ATT, node_id);
            doc_node_list.appendChild(node);

            System.out.println("\t" + solr_doc.toString());
        }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    
    return result;
        
    }

    protected String getCollectionCoreNamePrefix() {
        String site_name = this.router.getSiteName();
        String coll_name = this.cluster_name;
        String collection_core_name_prefix = site_name + "-" + coll_name;
        return collection_core_name_prefix;
    }
    
}