xconnection.java

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/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xalan.lib.sql;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Date;
import java.sql.Timestamp;
import java.sql.Time;
import java.util.Properties;
import java.util.Vector;
import java.util.StringTokenizer;
import java.lang.IllegalArgumentException;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import java.util.Vector;
import java.util.Enumeration;
import java.math.BigDecimal;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMManager;
import org.apache.xml.dtm.ref.DTMManagerDefault;
import org.apache.xpath.XPathContext;
import org.apache.xalan.extensions.ExpressionContext;
import org.apache.xpath.objects.XBooleanStatic;

import org.w3c.dom.*;
import java.sql.*;
import java.util.*;

/**
 * An XSLT extension that allows a stylesheet to
 * access JDBC data. 
 *
 * It is accessed by specifying a namespace URI as follows:
 * <pre>
 *    xmlns:sql="http://xml.apache.org/xalan/sql"
 * </pre>
 *
 * From the stylesheet perspective,
 * XConnection provides 3 extension functions: new(),
 * query(), and close().
 * Use new() to call one of XConnection constructors, which
 * establishes a JDBC driver connection to a data source and
 * returns an XConnection object.
 * Then use the XConnection object query() method to return a
 * result set in the form of a row-set element.
 * When you have finished working with the row-set, call the
 * XConnection object close() method to terminate the connection.
 */
public class XConnection
{

  /**
   * Flag for DEBUG mode
   */
  private static final boolean DEBUG = false;

  /**
   * The Current Connection Pool in Use. An XConnection can only
   * represent one query at a time, prior to doing some type of query.
   */
  private ConnectionPool m_ConnectionPool = null;

  /**
   * If a default Connection Pool is used. i.e. A connection Pool
   * that is created internally, then do we actually allow pools
   * to be created. Due to the archititure of the Xalan Extensions,
   * there is no notification of when the Extension is being unloaded and
   * as such, there is a good chance that JDBC COnnections are not closed.
   * A finalized is provided to try and catch this situation but since
   * support of finalizers is inconsistant across JVM's this may cause
   * a problem. The robustness of the JDBC Driver is also at issue here.
   * if a controlled shutdown is provided by the driver then default
   * conntectiom pools are OK.
   */
  private boolean m_DefaultPoolingEnabled = false;


  /**
   * As we do queries, we will produce SQL Documents. Any ony may produce
   * one or more SQL Documents so that the current connection information
   * may be easilly reused. This collection will hold a collection of all
   * the documents created. As Documents are closed, they will be removed
   * from the collection and told to free all the used resources.
   */
  private Vector m_OpenSQLDocuments = new Vector();


  /**
   * Let's keep a copy of the ConnectionPoolMgr in
   * alive here so we are keeping the static pool alive
   * We will also use this Pool Manager to register our default pools.
   */
  private ConnectionPoolManager m_PoolMgr = new ConnectionPoolManager();

  /**
   * For PreparedStatements, we need a place to
   * to store the parameters in a vector.
   */
  private Vector m_ParameterList = new Vector();

  /**
   * Allow the SQL Extensions to return null on error. The Error information will
   * be stored in a seperate Error Document that can easily be retrived using the
   * getError() method.
   * %REVIEW% This functionality will probably be buried inside the SQLDocument.
   */
  private SQLErrorDocument m_Error = null;

  /**
   */
  private boolean m_IsDefaultPool = false;

  /**
   * This flag will be used to indicate to the SQLDocument to use
   * Streaming mode. Streeaming Mode will reduce the memory footprint
   * to a fixed amount but will not let you traverse the tree more than
   * once since the Row data will be reused for every Row in the Query.
   */
  private boolean m_IsStreamingEnabled = true;

  /**
   */
  public XConnection( )
  {
  }

  // The original constructors will be kept around for backwards
  // compatibility. Future Stylesheets should use the approaite
  // connect method to receive full error information.
  //
  /**
   * @param exprContext
   * @param ConnPoolName
   */
  public XConnection( ExpressionContext exprContext, String ConnPoolName )
  {
    connect(exprContext, ConnPoolName);
  }

  /**
   * @param exprContext
   * @param driver
   * @param dbURL
   */
  public XConnection( ExpressionContext exprContext, String driver, String dbURL )
  {
    connect(exprContext, driver, dbURL);
  }

  /**
   * @param exprContext
   * @param list
   */
  public XConnection( ExpressionContext exprContext, NodeList list )
  {
    connect(exprContext, list);
  }

  /**
   * @param exprContext
   * @param driver
   * @param dbURL
   * @param user
   * @param password
   */
  public XConnection( ExpressionContext exprContext, String driver, String dbURL, String user, String password )
  {
    connect(exprContext, driver, dbURL, user, password);
  }

  /**
   * @param exprContext
   * @param driver
   * @param dbURL
   * @param protocolElem
   */
  public XConnection( ExpressionContext exprContext, String driver, String dbURL, Element protocolElem )
  {
    connect(exprContext, driver, dbURL, protocolElem);
  }


  /**
   * Create an XConnection using the name of an existing Connection Pool
   * @param exprContext
   * @param ConnPoolName
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, String ConnPoolName )
  {
    try
    {
      m_ConnectionPool = m_PoolMgr.getPool(ConnPoolName);

      if (m_ConnectionPool == null)
        throw new java.lang.IllegalArgumentException("Invalid Pool Name");

      m_IsDefaultPool = false;
      return new XBooleanStatic(true);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }

  }

  /**
   * Create an XConnection object with just a driver and database URL.
   * @param exprContext
   * @param driver JDBC driver of the form foo.bar.Driver.
   * @param dbURL database URL of the form jdbc:subprotocol:subname.
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, String driver, String dbURL )
  {
    try
    {
      init(driver, dbURL, new Properties());
      return new XBooleanStatic(true);
    }
    catch(SQLException e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
  }

  /**
   * @param exprContext
   * @param protocolElem
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, Element protocolElem )
  {
    try
    {
      initFromElement(protocolElem);
      return new XBooleanStatic(true);
    }
    catch(SQLException e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
  }

  /**
   * @param exprContext
   * @param list
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, NodeList list )
  {
    try
    {
      initFromElement( (Element) list.item(0) );
      return new XBooleanStatic(true);
    }
    catch(SQLException e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
  }

  /**
   * Create an XConnection object with user ID and password.
   * @param exprContext
   * @param driver JDBC driver of the form foo.bar.Driver.
   * @param dbURL database URL of the form jdbc:subprotocol:subname.
   * @param user user ID.
   * @param password connection password.
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, String driver, String dbURL, String user, String password )
  {
    try
    {
      Properties prop = new Properties();
      prop.put("user", user);
      prop.put("password", password);

      init(driver, dbURL, prop);

      return new XBooleanStatic(true);
    }
    catch(SQLException e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
  }


  /**
   * Create an XConnection object with a connection protocol
   * @param exprContext
   * @param driver JDBC driver of the form foo.bar.Driver.
   * @param dbURL database URL of the form jdbc:subprotocol:subname.
   * @param protocolElem list of string tag/value connection arguments,
   * normally including at least "user" and "password".
   * @return
   */
  public XBooleanStatic connect( ExpressionContext exprContext, String driver, String dbURL, Element protocolElem )
  {
    try
    {
      Properties prop = new Properties();

      NamedNodeMap atts = protocolElem.getAttributes();

      for (int i = 0; i < atts.getLength(); i++)
      {
        prop.put(atts.item(i).getNodeName(), atts.item(i).getNodeValue());
      }

      init(driver, dbURL, prop);

      return new XBooleanStatic(true);
    }
    catch(SQLException e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
    catch (Exception e)
    {
      buildErrorDocument(exprContext, e);
      return new XBooleanStatic(false);
    }
  }


  /**
   * Allow the database connection information to be sepcified in
   * the XML tree. The connection information could also be
   * externally originated and passed in as an XSL Parameter.
   * The required XML Format is as follows.
   * A document fragment is needed to specify the connection information
   * the top tag name is not specific for this code, we are only interested
   * in the tags inside.
   * <DBINFO-TAG>
   * Specify the driver name for this connection pool
   * <dbdriver>drivername</dbdriver>
   * Specify the URL for the driver in this connection pool
   * <dburl>url</dburl>
   * Specify the password for this connection pool
   * <password>password</password>
   * Specify the username for this connection pool
   * <user>username</user>
   * You can add extra protocol items including the User Name & Password
   * with the protocol tag. For each extra protocol item, add a new element
   * where the name of the item is specified as the name attribute and
   * and its value as the elements value.
   * <protocol name="name of value">value</protocol>
   * </DBINFO-TAG>
   * @param e
   * @return
   * @throws SQLException
   */
  private void initFromElement( Element e )throws SQLException
  {

    Properties prop = new Properties();
    String driver = "";
    String dbURL = "";
    Node n = e.getFirstChild();

    if (null == n) return; // really need to throw an error

    do
    {
      String nName = n.getNodeName();

      if (nName.equalsIgnoreCase("dbdriver"))
      {
        driver = "";
        Node n1 = n.getFirstChild();
        if (null != n1)
        {
          driver = n1.getNodeValue();
        }