W3CHINA.ORG讨论区--Jena文档《An Introduction to RDF and the Jena RDF API》的译文

import java.util.ArrayList;
import java.util.List;

import com.hp.hpl.jena.db.*;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.query.Query;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
import com.hp.hpl.jena.query.QuerySolutionMap;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.query.ResultSetFormatter;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.sparql.algebra.Algebra;
import com.hp.hpl.jena.sparql.algebra.Op;
import com.hp.hpl.jena.sparql.algebra.op.OpBGP;
import com.hp.hpl.jena.sparql.core.BasicPattern;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sparql.engine.QueryIterator;
import com.hp.hpl.jena.sparql.engine.ResultSetStream;
import com.hp.hpl.jena.sparql.engine.binding.Binding;
import com.hp.hpl.jena.sparql.util.FmtUtils;
import com.hp.hpl.jena.sparql.util.IndentedWriter;

/**
* Executes an RDQL query to find the hypernym of a given word
*/
public class FindHypernym {

/** MySQL driver classname */
private static final String mysqlDriver = "com.mysql.jdbc.Driver";

/** URL of database to use */
private static final String DB_URL = "jdbc:mysql://localhost/jena";
private static final String DB_TYPE = "MySQL";

/** User credentials */
private static final String DB_USER = "user";
private static final String DB_PASSWORD = "password";

/** Name of the Jena model to create */
private static final String MODEL_NAME = "wordnet";

static public final String NL = System.getProperty("line.separator");

/**
* Finds the hypernym of a word given on the commandline
*/
private static void printUsage() {
  System.out.print("\nUsage:\n");
  System.out.print("\tFindHypernym <hyponym>\n\n");
  System.out.print("\thyponym\t- The word to find hypernyms for\n");
}
public static void doSearch(Model m,String s){
  String BASE = "http://www.cogsci.princeton.edu/~wn/schema/" ;
  //Var var_hyponym = Var.alloc("hyponym") ;
        Var var_firstconcept = Var.alloc("firstconcept") ;
        Var var_hypernym = Var.alloc("hypernym");
        Var var_secondconcept = Var.alloc("secondconcept");
        Var var_definition = Var.alloc("definition");

        //WorkingVar wvar_hyponym = new WorkingVar();
  //wvar_hyponym.setString(s);
  Var var_hyponym=Var.alloc("hyponym");
  System.out.println(var_hyponym.toString());
        BasicPattern bp = new BasicPattern() ;
        bp.add(new Triple(var_firstconcept, Node.createURI(BASE+"wordForm"), var_hyponym)) ;
        bp.add(new Triple(var_firstconcept, Node.createURI(BASE+"hyponymOf"), var_secondconcept)) ;
        bp.add(new Triple(var_secondconcept, Node.createURI(BASE+"wordForm"), var_hypernym)) ;
        bp.add(new Triple(var_secondconcept, Node.createURI(BASE+"glossaryEntry"), var_definition)) ;

        Op op = new OpBGP(bp) ;
        m.write(System.out, "TTL") ;
        System.out.println("--------------") ;
        System.out.print(op) ;
        System.out.println("--------------") ;

        // ---- Execute expression
        QueryIterator qIter = Algebra.exec(op, m.getGraph()) ;

        // -------- Either read the query iterator directly ...
        if ( false )
        {
            for ( ; qIter.hasNext() ; )
            {
                Binding b = qIter.nextBinding() ;
                Node n = b.get(var_hypernym) ;
                System.out.println(FmtUtils.stringForNode(n)) ;
                Node n1 = b.get(var_definition) ;
                System.out.println(FmtUtils.stringForNode(n1)) ;
                System.out.println(b) ;
            }
            qIter.close() ;
        }
        else
        {
            // -------- Or make ResultSet from it (but not both - reading an
            //          iterator consumes the current solution)
            List varNames = new ArrayList() ;
            varNames.add("hypernym") ;
            varNames.add("definition") ;
            ResultSet rs = new ResultSetStream(varNames, m, qIter);
            ResultSetFormatter.out(rs) ;
            qIter.close() ;
        }
        //System.exit(0) ;
}
public static void main(String args[]) {

  // Check that the user provided a single argument
  if (args.length != 1) {
   printUsage();
   System.exit(-1);
  }

  try {
   // Instantiate database driver
   Class.forName(mysqlDriver);
  } catch (ClassNotFoundException e) {
   System.err.println("MySQL driver class not found");
   System.exit(-1);
  }

  // Get a connection to the db
  DBConnection connection = new DBConnection(DB_URL, DB_USER,
    DB_PASSWORD, DB_TYPE);

  // Get hold of the existing wordnet model
  ModelRDB model = ModelRDB.open(connection, MODEL_NAME);

  String prolog = "PREFIX wn: <http://www.cogsci.princeton.edu/~wn/schema/>";
  // Create a query

  String queryString = prolog + NL + "SELECT ?hypernym ?definition "
    + "WHERE {?firstconcept wn:wordForm ?hyponym. "
    + "?firstconcept wn:hyponymOf ?secondconcept. "
    + "?secondconcept wn:wordForm ?hypernym. "
    + "?secondconcept wn:glossaryEntry ?definition.} ";

  Query query = QueryFactory.create(queryString);
  query.serialize(new IndentedWriter(System.out, true));
  System.out.println();

  RDFNode hyponym = model.createLiteral(args[0]);
  //store the node in a QuerySolutionMap
  QuerySolutionMap initialBindings = new QuerySolutionMap();
  initialBindings.add("hyponym", hyponym);

  QueryExecution qexec = QueryExecutionFactory.create(query, model,initialBindings);
  ResultSet results = qexec.execSelect();
  // Output the results
  System.out.println("Hypernyms found for '" + args[0] + "':");
  System.out.println();
  ResultSetFormatter.out(System.out, results, query);
  qexec.close();
  System.out.println("========================");
  //doSearch(model,args[0]);
  try {
   // Close the database connection
   connection.close();
  } catch (java.sql.SQLException e) {
  }
}

// results.close() ;
/* Property formword=model.CreateResouces()
/*
* ResIterator iter = model.listSubjectsWithProperty(); if (iter.hasNext()) {
* System.out.println("The database contains vcards for:"); while
* (iter.hasNext()) { System.out.println(" " + iter.nextStatement()
* .getProperty(VCARD.FN) .getString()); } } else { System.out.println("No
* vcards were found in the database"); }
*/
}

运行结果：
  1 PREFIX  wn:   <http://www.cogsci.princeton.edu/~wn/schema/>
  2
  3 SELECT  ?hypernym ?definition
  4 WHERE
  5   { ?firstconcept
  6               wn:wordForm       ?hyponym ;
  7               wn:hyponymOf      ?secondconcept .
  8     ?secondconcept
  9               wn:wordForm       ?hypernym ;
10               wn:glossaryEntry  ?definition .
11   }

Hypernyms found for 'tiger':

--------------------------------------------------------------------------------------------
| hypernym     | definition                                                                |
============================================================================================
| "big cat"    | "any of several large cats typically able to roar and living in the wild" |
| "cat"        | "any of several large cats typically able to roar and living in the wild" |
| "soul"       | "a human being; \"there was too much for one person to do\""              |
| "human"      | "a human being; \"there was too much for one person to do\""              |
| "individual" | "a human being; \"there was too much for one person to do\""              |
| "mortal"     | "a human being; \"there was too much for one person to do\""              |
| "person"     | "a human being; \"there was too much for one person to do\""              |
| "somebody"   | "a human being; \"there was too much for one person to do\""              |
| "someone"    | "a human being; \"there was too much for one person to do\""              |
--------------------------------------------------------------------------------------------
嗯，好象是运行成功了，不明白preson,somebody怎么也是上位词了呢。
还有根据Algebra例子写的一个doSearch方法没完成，请高手指点一下，谢谢！


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