Package virtuoso.jena.driver

Source Code of virtuoso.jena.driver.VirtuosoQueryExecution$VResultSet

/*
*  $Id$
*
*  This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
*  project.
*
*  Copyright (C) 1998-2014 OpenLink Software
*
*  This project is free software; you can redistribute it and/or modify it
*  under the terms of the GNU General Public License as published by the
*  Free Software Foundation; only version 2 of the License, dated June 1991.
*
*  This program is distributed in the hope that it will be useful, but
*  WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
*  General Public License for more details.
*
*  You should have received a copy of the GNU General Public License along
*  with this program; if not, write to the Free Software Foundation, Inc.,
*  51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/

package virtuoso.jena.driver;

import java.util.*;
import java.io.*;
import java.net.*;
import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSetMetaData;

import virtuoso.sql.*;

import com.hp.hpl.jena.shared.*;
import com.hp.hpl.jena.query.ResultSet;
import com.hp.hpl.jena.query.Dataset;
import com.hp.hpl.jena.query.QueryExecution;

import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.rdf.model.*;

import com.hp.hpl.jena.sparql.engine.binding.BindingMap;
import com.hp.hpl.jena.sparql.engine.binding.Binding;
import com.hp.hpl.jena.sparql.engine.ResultSetStream;
import com.hp.hpl.jena.sparql.engine.QueryIterator;
import com.hp.hpl.jena.sparql.engine.iterator.QueryIterConcat;
import com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP;
import com.hp.hpl.jena.sparql.engine.iterator.QueryIterSingleton;
import com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorResultSet;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sparql.core.ResultBinding;
import com.hp.hpl.jena.sparql.util.Context;
import com.hp.hpl.jena.sparql.util.ModelUtils;
import com.hp.hpl.jena.util.FileManager;
import com.hp.hpl.jena.query.*;

import virtuoso.jdbc3.VirtuosoConnectionPoolDataSource;

public class VirtuosoQueryExecution  implements QueryExecution
{
    private QueryIterConcat output = null;
    private String virt_graph = null;
    private VirtGraph graph;
    private String virt_query;
    private QuerySolution m_arg = null;

    private java.sql.Statement stmt = null;


    public VirtuosoQueryExecution (String query, VirtGraph _graph)
    {
  graph = _graph;
  virt_graph = graph.getGraphName ();
  virt_query = query;
    }


    public ResultSet execSelect()
    {
      try {
        stmt = graph.createStatement();
        java.sql.ResultSet rs = stmt.executeQuery(getQuery());

        return new VResultSet(graph, rs);
      catch(Exception e) {
        throw new JenaException("Can not create ResultSet.:"+e);
      }
    }



    public void setFileManager(FileManager arg)
    {
      throw new JenaException("UnsupportedMethodException");
    }


    public void setInitialBinding(QuerySolution arg)
    {
      m_arg = arg;
    }

    public Dataset getDataset()
    {
      return new VirtDataSource(graph);
    }


    public Context getContext()
    {
      return null;
    }


    public Model execConstruct()
    {
      return execConstruct(ModelFactory.createDefaultModel());
    }


    public Model execConstruct(Model model)
    {
      try {
        stmt = graph.createStatement();
        java.sql.ResultSet rs = stmt.executeQuery(getQuery());
        ResultSetMetaData rsmd = rs.getMetaData();

        while(rs.next())
        {
          Node s = VirtGraph.Object2Node(rs.getObject(1));
          Node p = VirtGraph.Object2Node(rs.getObject(2));
          Node o = VirtGraph.Object2Node(rs.getObject(3));
          com.hp.hpl.jena.rdf.model.Statement st = ModelUtils.tripleToStatement(model, new Triple(s, p, o));
          if (st != null)
            model.add(st);
       
        rs.close();
        stmt.close();
        stmt = null;

      } catch (Exception e) {
        throw new JenaException("Convert results are FAILED.:"+e);
      }
      return model;
    }


 
    public Model execDescribe()
    {
      return execDescribe(ModelFactory.createDefaultModel());
    }

    public Model execDescribe(Model model)
    {
      try {
        stmt = graph.createStatement();
        java.sql.ResultSet rs = stmt.executeQuery(getQuery());
        ResultSetMetaData rsmd = rs.getMetaData();
        while(rs.next())
        {
          Node s = VirtGraph.Object2Node(rs.getObject(1));
          Node p = VirtGraph.Object2Node(rs.getObject(2));
          Node o = VirtGraph.Object2Node(rs.getObject(3));

          com.hp.hpl.jena.rdf.model.Statement st = ModelUtils.tripleToStatement(model, new Triple(s, p, o));
          if (st != null)
            model.add(st);
       
        rs.close();
        stmt.close();
        stmt = null;

      } catch (Exception e) {
        throw new JenaException("Convert results are FAILED.:"+e);
      }
      return model;
    }


    public boolean execAsk()
    {
      boolean ret = false;

      try {
        stmt = graph.createStatement();
        java.sql.ResultSet rs = stmt.executeQuery(getQuery());
        ResultSetMetaData rsmd = rs.getMetaData();

        while(rs.next())
        {
          if (rs.getInt(1) == 1)
            ret = true;
       
        rs.close();
        stmt.close();
        stmt = null;

      } catch (Exception e) {
        throw new JenaException("Convert results are FAILED.:"+e);
      }
      return ret;
    }


    public void abort()
    {
      if (stmt != null)
        try {
          stmt.cancel();
        } catch (Exception e) {}
    }


    public void close()
    {
      if (stmt != null)
        try {
          stmt.cancel();
          stmt.close();
        } catch (Exception e) {}
    }


    private String substBindings(String query)
    {
      if (m_arg == null)
        return query;

      StringBuffer buf = new StringBuffer();
      String delim = " ,)(;.";
      int i = 0;
      char ch;
      int qlen = query.length();
      while( i < qlen) {
        ch = query.charAt(i++);
        if (ch == '\\') {
    buf.append(ch);
          if (i < qlen)
            buf.append(query.charAt(i++));

        } else if (ch == '"' || ch == '\'') {
          char end = ch;
          buf.append(ch);
          while (i < qlen) {
            ch = query.charAt(i++);
            buf.append(ch);
            if (ch == end)
              break;
          }
        } else  if ( ch == '?' ) {  //Parameter
          String varData = null;
          int j = i;
          while(j < qlen && delim.indexOf(query.charAt(j)) < 0) j++;
          if (j != i) {
            String varName = query.substring(i, j);
            RDFNode val = m_arg.get(varName);
            if (val != null) {
              varData = VirtGraph.Node2Str(val.asNode());
              i=j;
            }
          }
          if (varData != null)
            buf.append(varData);
          else
            buf.append(ch);
  } else {
          buf.append(ch);
      }
      }
      return buf.toString();
    }

   
    private String getQuery()
    {
  StringBuffer sb = new StringBuffer("sparql\n ");
 
  if (graph.getRuleSet()!= null)
          sb.append(" define input:inference '"+graph.getRuleSet()+"'\n");

        if (graph.getSameAs())
          sb.append(" define input:same-as \"yes\"\n");

        if (!graph.getReadFromAllGraphs())
    sb.append(" define input:default-graph-uri <" + graph.getGraphName() + "> \n");

        sb.append(substBindings(virt_query));

        return sb.toString();
    }

   
    ///=== Inner class ===========================================
    public class VResultSet implements com.hp.hpl.jena.query.ResultSet
    {
      ResultSetMetaData rsmd;
      java.sql.ResultSet rs;
      boolean v_finished = false;
      boolean v_prefetched = false;
      VirtModel m;
      Binding v_row;
      List<String> resVars =new LinkedList();
      int row_id = 0;


        protected VResultSet(VirtGraph _g, java.sql.ResultSet _rs)
  {
    rs = _rs;
    m = new VirtModel(_g);

          try {
            rsmd = rs.getMetaData();
      for(int i = 1; i <= rsmd.getColumnCount(); i++)
        resVars.add(rsmd.getColumnLabel(i));

      if (virt_graph != null && !virt_graph.equals("virt:DEFAULT"))
        resVars.add("graph");
    }
    catch(Exception e)
    {
            throw new JenaException("ViruosoResultBindingsToJenaResults is FAILED.:"+e);
    }
  }
       
        public boolean hasNext()
        {
           if (!v_finished && !v_prefetched)
             moveForward();
    return !v_finished;
        }
   
        public QuerySolution next()
        {
          Binding binding = nextBinding() ;

    if (v_finished)
      throw new NoSuchElementException();
 
          return new ResultBinding(m, binding) ;
        }

        public QuerySolution nextSolution()
        {
          return next();
        }

        public Binding nextBinding()
        {
          if (!v_finished && !v_prefetched)
      moveForward();

    v_prefetched = false;

    if (v_finished)
      throw new NoSuchElementException();
 
          return v_row;
        }
   
        public int getRowNumber()
        {
          return row_id;
        }
   
        public List<String> getResultVars()
        {
          return resVars;
        }

        public Model getResourceModel()
        {
          return m;
        }

  protected void finalize() throws Throwable
  {
    if (!v_finished)
      try {
        close();
      } catch (Exception e) {}
  }

  protected void moveForward() throws JenaException
  {
    try
    {
      if (!v_finished && rs.next())
      {
    extractRow();
    v_prefetched = true;
      }
      else
    close();
    }
    catch (Exception e)
    {
            throw new JenaException("Convert results are FAILED.:"+e);
    }
  }

  protected void extractRow() throws Exception
  {
          v_row = new BindingMap();
          row_id++;

          try {
      for(int i = 1; i <= rsmd.getColumnCount(); i++) {
        Node n = VirtGraph.Object2Node(rs.getObject(i));
        if (n != null)
          v_row.add(Var.alloc(rsmd.getColumnLabel(i)), n);
      }

      if (virt_graph != null && !virt_graph.equals("virt:DEFAULT"))
        v_row.add(Var.alloc("graph"), Node.createURI(virt_graph));
    }
    catch(Exception e)
    {
            throw new JenaException("ViruosoResultBindingsToJenaResults is FAILED.:"+e);
    }
  }

        public void remove() throws java.lang.UnsupportedOperationException
        {
          throw new UnsupportedOperationException(this.getClass().getName()+".remove") ;
        }

        private void close()
        {
    if (!v_finished)
    {
      if (rs != null)
      {
        try {
                rs.close();
                rs = null;
              } catch (Exception e) { }
            }
          }
          v_finished = true;
        }


    }
}
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