// https://github.com/BorderCloud/SPARQL-JAVA
import com.bordercloud.sparql.Endpoint;
import com.bordercloud.sparql.EndpointException;
import java.util.ArrayList;
import java.util.HashMap;

public class Main {

    public static void main(String[] args) {
        String endpointUrl = "http://sparql.example/endpoint";

        String querySelect = "# cats\n" +
                "SELECT ?cat ?catLabel WHERE {\n" +
                "  ?cat wdt:P31 wd:Q146.\n" +
                "  SERVICE wikibase:label { bd:serviceParam wikibase:language \"[AUTO_LANGUAGE],en\". }\n" +
                "}\n" +
                "";

        try {
            HashMap data = retrieveData(endpointUrl, querySelect);
            printResult(data, 30);
        } catch (EndpointException eex) {
            eex.printStackTrace();
        }
    }

    public static HashMap<String, HashMap> retrieveData(String endpointUrl, String query) throws EndpointException {
        Endpoint sp = new Endpoint(endpointUrl, false);
        sp.setUserAgentRequestHeader("WDQS-Example Java"); // TODO adjust this; see https://w.wiki/CX6
        HashMap<String, HashMap> rs = sp.query(query);
        return rs;
    }

    public static void printResult(HashMap<String, HashMap> rs , int size) {
      for (String variable : (ArrayList<String>) rs.get("result").get("variables")) {
        System.out.print(String.format("%-"+size+"."+size+"s", variable ) + " | ");
      }
      System.out.print("\n");
      for (HashMap value : (ArrayList<HashMap>) rs.get("result").get("rows")) {
        for (String variable : (ArrayList<String>) rs.get("result").get("variables")) {
          System.out.print(String.format("%-"+size+"."+size+"s", value.get(variable)) + " | ");
        }
        System.out.print("\n");
      }
    }
}