Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A class represent a connection object, it includes connction 

 *    itself, index, status, age and usageCount.

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Jing Tao

 *    Release: @release@

 *

 *   '$Author: tao $'

 *     '$Date: 2002-05-16 17:43:38 -0700 (Thu, 16 May 2002) $'

 * '$Revision: 1088 $'

 *

 * 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;

import java.io.*;

import java.sql.*;

/**

 * A class represent a connection object, it includes connection itself, 

 * index, status, age, createtime, connection time, usageCount, warning message

 */

 public class DBConnection

{

  private Connection conn;

  private String tag;//to idenify this object

  private int status;// free or using

  private long age;

  private long createTime;

  private long connectionTime; //how long it use for connections, 

                               //it is accumulated

  private long checkOutTime;

  private int usageCount;// how many time the connection was used

  private SQLWarning warningMessage;

  private String  DBDriver=MetaCatUtil.getOption("dbDriver");

  private String  DBConnectedJDBC=MetaCatUtil.getOption("defaultDB");

  private String  userName=MetaCatUtil.getOption("user");

  private String  passWord=MetaCatUtil.getOption("password");

  /**

   * Default constructor of the DBConnection class 

   * It will create a new DBConnection with a new Connection

   * 

   */

  public DBConnection() throws SQLException

  {

    conn = openConnection();

    tag = conn.toString();

    status = 0;

    age = 0;

    createTime = System.currentTimeMillis();

    connectionTime = 0;

    checkOutTime = 0;

    usageCount= 0;

    warningMessage = null;

  }

  /**

   * construct an instance of the DBQConnection class 

   *

   * @param conn, the JDBC connection itself.

   * @param status, the status of this connection, free or using

   * @param age,the age of the connection 

   * @param usageCount of the connection

   */

  public DBConnection (Connection conn, int status, long age, 

                        long createTime, long connectionTime, int usageCount)

                               throws SQLException

  {

    this.conn = conn;

    this.tag = conn.toString();

    this.status = status;

    this.age = age;

    this.createTime = createTime;

    this.connectionTime = connectionTime;

    this.usageCount = usageCount;

    try

    {

      this.warningMessage = conn.getWarnings();

    }

    catch (SQLException e)

    {

      throw e;

    }

  }

  /**

   * get the  connetion from the object

   */

  public Connection getConnection()

  {

    return conn;

  }

  /**

   * Set a connection to this object

   * @param myDBConnection, the connection which will be assign to this object

   */

  public void setConnection( Connection myConnection)

  {

    this.conn = myConnection;

  }

  /**

   * get the db connetion tag from the object

   */

  public String getTag()

  {

    return tag;

  }

  /**

   * Set a connection status to this object

   * @param myTag, the tag which will be assign to this object

   */

  public void setTag(String myTag)

  {

    this.tag = myTag;

  }

  /**

   * get the db connetion status from the object

   */

  public int getStatus()

  {

    return status;

  }

  /**

   * Set a connection status to this object

   * @param myStatus, the status which will be assign to this object

   * 0 is free, 1 is using

   */

  public void setStatus(int myStatus)

  {

    this.status = myStatus;

  }

  /**

   * get the db connetion age from the object

   */

  public long getAge()

  {

    return (System.currentTimeMillis() - createTime);

  }

  /**

   * Set a connection age to this object

   * @param myAge, the Age which will be assign to this object

   */

  public void setAge(long myAge)

  {

    this.age = myAge;

  }  

  /**

   * get the db connetion created time from the object

   */

  public long getCreateTime()

  {

    return createTime;

  }

  /**

   * Set a usage number to this object

   * @param myCreateTime, the create time which will be assign to this object

   */

  public void setCreateTime(long myCreateTime)

  {

    this.createTime = myCreateTime;

  }

  /**

   * get the how long db connetion usedfrom the object

   */

  public long getConnectionTime()

  {

    return connectionTime;

  }

  /**

   * Set a connection time to this object

   * It is accumulated

   * @param myConnectionTime, the connection time which will assign to

   * this object

   */

  public void setConnectionTime(long myConnectionTime)

  {

    this.connectionTime = this.connectionTime + myConnectionTime;

  }

    /**

   * get the how long db connetion usedfrom the object

   */

  public long getCheckOutTime()

  {

    return checkOutTime;

  }

  /**

   * Set check out time to this object

   * @param myCheckOutTime, the check out time which will assign to

   * this object

   */

  public void setCheckOutTime(long myCheckOutTime)

  {

    this.checkOutTime = myCheckOutTime;

  }

  /**

   * get the db connetion usage times from the object

   */

  public int getUsageCount()

  {

    return usageCount;

  }

  /**

   * Set a usage number to this object

   * @param myUsageCount, number of usage which will be assign to this object

   */

  public void setUsageCount(int myUsageCount)

  {

    this.usageCount = myUsageCount;

  }

  /**

   * Increase a usage number to this object

   * @param myUsageCount, number of usage which will be add to this object

   */

  public void increaseUsageCount(int myUsageCount)

  {

    this.usageCount = this.usageCount + myUsageCount;

  }  

  /**

   * get the db connetion waring message from the object

   */

  public SQLWarning getWarningMessage()

  {

    return warningMessage;

  }

  /**

   * Set a warning message to this object

   * @param myWarningMessage, the waring which will be assign to this object

   */

  public void setWarningMessage(SQLWarning myWarningMessage)

  {

     this.warningMessage = myWarningMessage;

  }

  /**

   * Close a DBConnection object

   */

  public void close() throws SQLException

  {

    conn.close();

    conn=null;

    tag = null;

    status = 0;

    age = 0;

    createTime = System.currentTimeMillis();

    connectionTime = 0;

    checkOutTime = 0;

    usageCount= 0;

    warningMessage = null;

  }

    /** 

   * Method to establish a JDBC database connection 

   */

  private Connection openConnection()

                  throws SQLException 

  {

    return openConnection(DBDriver, DBConnectedJDBC, userName, passWord);

  }//openDBConnection

  /** 

   * Method to establish a JDBC database connection 

   *

   * @param dbDriver the string representing the database driver

   * @param connection the string representing the database connectin parameters

   * @param user name of the user to use for database connection

   * @param password password for the user to use for database connection

   */

  private Connection openConnection(String dbDriver, String connection,

                String user, String password)

                throws SQLException

 {

     // Load the Oracle JDBC driver

     try

     {

       Class.forName (dbDriver);

     }

     catch (ClassNotFoundException e)

     {

       MetaCatUtil.debugMessage("Error in DBConnectionPool "+e.getMessage(),30);

       return null;

     }

     // Connect to the database

     Connection conn = DriverManager.getConnection( connection, user, password);

     return conn;

  }//OpenDBConnection

}//DBConnection class