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Example: JDBC Connection Pooling in DataDirect XQuery®

The following code sample shows a servlet using JDBC connection pooling in DataDirect XQuery®.

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import com.ddtek.xquery3.XQConnection;
import com.ddtek.xquery3.XQException;
import com.ddtek.xquery3.XQExpression;
import com.ddtek.xquery3.XQSequence;

import com.ddtek.xquery3.jdbc.XQueryConnection;

/**
 * DataDirect Servlet example demonstrating the integration with JDBC Connection Pooling
 */
public class DDXQServlet extends HttpServlet {
	
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
    throws ServletException, IOException {

	  Connection jdbc_c = null;
	  XQExpression xqj_e = null;
	  	
		try {
			Context initContext = new InitialContext();
			Context envContext  = (Context)initContext.lookup("java:/comp/env");
			DataSource jdbc_ds = (DataSource)envContext.lookup("jdbc/DDXQExample");
			jdbc_c = jdbc_ds.getConnection();
	
			PrintWriter out = response.getWriter();
			
			XQConnection xqj_c = XQueryConnection.getXQConnection(jdbc_c);
	
			xqj_e = xqj_c.createExpression();
			XQSequence xqj_s = xqj_e.executeQuery(
				"	<b>Current date: </b>,current-date(),<br/>," +
				"	<b>Current time: </b>,current-time(), " +
				" <table border='1'> "+
				"	  <tr> "+
				"	    <th>User</th> "+
				"	    <th>Stock</th> "+
				"	    <th>Shares</th> "+
				"	  </tr> "+
				"	  { "+
				"	  for $item in collection('holdings')/holdings "+
				"	  return "+
				"	    <tr> "+
				"	      <td>{$item/userid/data(.)}</td> "+
				"	      <td>{$item/stockticker/data(.)}</td> "+
				"	      <td>{$item/shares/data(.)}</td> "+
				"	    </tr> "+
				"	  } "+
				"	</table> ");
		    				
			xqj_s.writeSequence(out, new Properties());
	
			out.close();
		}
		catch(Exception e){
			throw new ServletException(e);
		}
		finally {
			if (xqj_e != null) try{xqj_e.close();} catch (XQException e) {}
			if (jdbc_c != null) try{jdbc_c.close();} catch (SQLException e) {}
		}
	 }

}