Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2003 Regents of the University of California.

 *

 * Author: John Harris

 * '$Date: 2006-02-19 21:11:53 -0800 (Sun, 19 Feb 2006) $'

 * '$Revision: 2910 $'

 *

 * This program 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; either version 2 of the License, or

 * (at your option) any later version.

 *

 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.spatial;

import java.io.File;

import java.io.FileReader;

import java.io.PrintWriter;

import java.io.IOException;

import java.io.StringReader;

import java.io.BufferedReader;

import java.io.Reader;

import java.io.FileInputStream;

import java.io.BufferedInputStream;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.ResourceBundle;

import java.util.Random;

import java.util.StringTokenizer;

import java.util.Properties;

import java.util.PropertyResourceBundle;

import java.util.Vector;

import java.util.Map;

import edu.ucsb.nceas.metacat.client.Metacat;

import edu.ucsb.nceas.metacat.DBConnection;

import edu.ucsb.nceas.metacat.client.MetacatFactory;

import edu.ucsb.nceas.metacat.client.MetacatAuthException;

import edu.ucsb.nceas.metacat.client.MetacatException;

import edu.ucsb.nceas.metacat.client.MetacatInaccessibleException;

import edu.ucsb.nceas.metacat.client.InsufficientKarmaException;

import edu.ucsb.nceas.utilities.IOUtil;

import java.sql.ResultSet;

import java.sql.PreparedStatement;

import org.apache.log4j.Logger;

import org.apache.log4j.BasicConfigurator;

import org.apache.log4j.PropertyConfigurator;

public class SpatialQueryProcessor {

  private String METACATURL =

      "http://nebulous.msi.ucsb.edu:9999/knp/metacat";

  private File QUERYFILE = null;

  private String MCUSER = "uid=harris,o=NCEAS,dc=ecoinformatics,dc=org";

  private String MCPASS = "yeahRight";

  private DBConnection dbconn;

  private static Logger log =

      Logger.getLogger(SpatialQueryProcessor.class.getName());

        /** constructor that uses the defaults **/

  public SpatialQueryProcessor() {

    try {

      dbconn = new DBConnection();

    } catch(java.sql.SQLException se) {

      log.fatal("Error connecting to the database ...");

      se.getMessage();

    }

  }

  /** call this after the processor is done **/

  protected void close() {

    try {

      dbconn.close();

    } catch(java.sql.SQLException se) {

      log.fatal("Error closing connecting to the database ...");

      se.getMessage();

    }

  }

  public SpatialQueryProcessor(String mcUser, String mcPass,

                               String metacatUrl, File queryFile) {

    log.debug("constructor called");

    this.METACATURL = metacatUrl;

    this.MCPASS = mcPass;

    this.MCUSER = mcUser;

    this.QUERYFILE = queryFile;

  }

  public String execute() throws IOException {

    FileReader queryFileReader = new FileReader(QUERYFILE);

    String res = runQuery((Reader) queryFileReader);

     return res;

  } protected MetacatSpatialDataset queryDatasetByCartesianBounds(float

                                                                  _xmin,

                                                                  float

                                                                  _ymin,

                                                                  float

                                                                  _xmax,

                                                                  float

                                                                  _ymax) {

    MetacatSpatialDataset _data = new MetacatSpatialDataset();

    // get all docid's 

    Vector _docs = queryAllDocids();

    // for each, see if they fall w/in bounds

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

      float _docMaxY =

          queryNorthBoundingCoordinate((String) _docs.elementAt(i));

      float _docMinY =

          querySouthBoundingCoordinate((String) _docs.elementAt(i));

      float _docMaxX =

          queryEastBoundingCoordinate((String) _docs.elementAt(i));

      float _docMinX =

          queryWestBoundingCoordinate((String) _docs.elementAt(i));

      // check if inside the bounding box

      if (_docMaxX <= _xmax && _docMaxX >= _xmin) {

        MetacatSpatialDocument _doc =

            new MetacatSpatialDocument((String) _docs.elementAt(i));

        _doc.setDocid((String) _docs.elementAt(i));

        // set the extents

        _data.add(_doc);

      }

    }

    return _data;

  }

  /**

   * Returns a Vector of all the docids in the xml_nodes tables

   */

  protected Vector queryAllDocids() {

    Vector _docs = new Vector();

    PreparedStatement pstmt = null;

    ResultSet rs = null;

    String query = "select distinct docid from xml_nodes";

    try {

      pstmt = dbconn.prepareStatement(query);

      pstmt.execute();

      rs = pstmt.getResultSet();

      while (rs.next()) {

        String docid = rs.getString(1);

        log.fatal("adding docid: " + docid);

        _docs.add(docid);

      }

      rs.close();

      pstmt.close();

    }

    catch(Exception e) {

      log.error("Error getting docids from queryAllDocids");

      e.printStackTrace();

    }

    return _docs;

  }

  /**

   * returns the north bounding coordinate -- this is a single point

   */

  private float queryNorthBoundingCoordinate(String docid) {

    float _coord = MetacatSpatialConstants.FLOAT_NULL;

    PreparedStatement pstmt = null;

    ResultSet rs = null;

    String query = "select docid, nodedata, nodeid from xml_nodes where "

        + "nodeid =(select  nodeid from  xml_nodes where docid  like '"

        + docid.trim() + "' and nodename like 'north%')+1;";

    try {

      pstmt = dbconn.prepareStatement(query);

      pstmt.execute();

      rs = pstmt.getResultSet();

      if (rs.next())

        _coord = rs.getFloat(2);

      rs.close();

      pstmt.close();

    }

    catch(Exception e) {

      log.error("Error getting docids from queryExtentsByDocid");

      e.printStackTrace();

    }

    return _coord;

  }

  /**

   * returns the east bounding coordinate -- this is a single point

   */

  private float queryEastBoundingCoordinate(String docid) {

    float _coord = MetacatSpatialConstants.FLOAT_NULL;

    PreparedStatement pstmt = null;

    ResultSet rs = null;

    String query = "select docid, nodedata, nodeid from xml_nodes where "

        + "nodeid =(select  nodeid from  xml_nodes where docid  like '"

        + docid.trim() + "' and nodename like 'east%')+1;";

    try {

      pstmt = dbconn.prepareStatement(query);

      pstmt.execute();

      rs = pstmt.getResultSet();

      if (rs.next())

        _coord = rs.getFloat(2);

      rs.close();

      pstmt.close();

    }

    catch(Exception e) {

      log.error("Error getting docids from queryExtentsByDocid");

      e.printStackTrace();

    }

    return _coord;

  }

  /**

   * returns the south bounding coordinate -- this is a single point

   */

  private float querySouthBoundingCoordinate(String docid) {

    float _coord = MetacatSpatialConstants.FLOAT_NULL;

    PreparedStatement pstmt = null;

    ResultSet rs = null;

    String query = "select docid, nodedata, nodeid from xml_nodes where "

        + "nodeid =(select  nodeid from  xml_nodes where docid  like '"

        + docid.trim() + "' and nodename like 'south%')+1;";

    try {

      pstmt = dbconn.prepareStatement(query);

      pstmt.execute();

      rs = pstmt.getResultSet();

      if (rs.next())

        _coord = rs.getFloat(2);

      rs.close();

      pstmt.close();

    }

    catch(Exception e) {

      log.error("Error getting docids from queryExtentsByDocid");

      e.printStackTrace();

    }

    return _coord;

  }

  /**

   * returns the west bounding coordinate -- this is a single point

   */

  private float queryWestBoundingCoordinate(String docid) {

    float _coord = MetacatSpatialConstants.FLOAT_NULL;

    PreparedStatement pstmt = null;

    ResultSet rs = null;

    String query = "select docid, nodedata, nodeid from xml_nodes where "

        + "nodeid =(select  nodeid from  xml_nodes where docid  like '"

        + docid.trim() + "' and nodename like 'west%')+1;";

    try {

      pstmt = dbconn.prepareStatement(query);

      pstmt.execute();

      rs = pstmt.getResultSet();

      if (rs.next())

        _coord = rs.getFloat(2);

      rs.close();

      pstmt.close();

    }

    catch(Exception e) {

      log.error("Error getting docids from queryExtentsByDocid");

      e.printStackTrace();

    }

    return _coord;

  }

  /**

   * Performs a spatial query given the docid as an input

   * 

   * @param docid -- the docid for which the extents are to be queried

   * @returns spatialextents -- the MetcataSpatialExtents object for this query

   */

  protected MetacatSpatialExtents queryExtentsByDocid(String docid) {

    MetacatSpatialExtents _extents = new MetacatSpatialExtents();

    float _northbc = queryNorthBoundingCoordinate(docid);

    float _eastbc = queryEastBoundingCoordinate(docid);

    float _southbc = querySouthBoundingCoordinate(docid);

    float _westbc = queryWestBoundingCoordinate(docid);

    if ((_northbc == _southbc) && (_eastbc == _westbc)) {

      _extents.setIsPoint(true);

    } else {

      _extents.setIsPoint(false);

    }

    _extents.setYMin((_southbc < _northbc ? _southbc : _northbc));

    _extents.setYMax((_southbc > _northbc ? _southbc : _northbc));

    _extents.setXMin((_westbc < _eastbc ? _westbc : _eastbc));

    _extents.setXMax((_westbc > _eastbc ? _westbc : _eastbc));

    _extents.setDocid(docid);

    return _extents;

  }

        /**

		* Query the Metacat Server to get a list of documents, 

		* if it doesn't exist there, from the backend storage server.

		* 

		* @param query the xml description of the query to run

		* @return String the XML document string of the result set

		* @throws QueryFailedException when any thing happens to prevent a query

		*  returns

		*/

  private String runQuery(Reader query) {

    String document = null;

    Reader xdoc = null;

    String error = null;

    try {

      log.debug("creating metacat instance with: " + METACATURL);

      Metacat m = MetacatFactory.createMetacatConnection(METACATURL);

      m.login(MCUSER, MCPASS);

      log.debug("metacat instance: " + m);

      xdoc = m.query(query);

      document = IOUtil.getAsString(xdoc, true);

      m.logout();

      if (document == null) {

        throw new QueryFailedException("Document String Was null");

      }

    }

    catch(Exception e) {

      e.printStackTrace();

    }

    return document;

  }

}