Data base connection polling

[santhosh.R gowda]

Dear all,

I had created one data base connection pooling which is of unlimited size.....

 
import java.util.*;
public abstract class ObjectPool<Connection> {
  private long expirationTime;

  private Hashtable<Connection, Long> locked, unlocked;

  public ObjectPool() {
    expirationTime = 30000; // 30 seconds
    locked = new Hashtable<Connection, Long>(10);
    unlocked = new Hashtable<Connection, Long>();
  }

  protected abstract Connection create();

  public abstract boolean validate(Connection o);

  public abstract void expire(Connection o);

  public synchronized Connection checkOut() {
    long now = System.currentTimeMillis();
    Connection t;
    if (unlocked.size() > 0) {
      Enumeration<Connection> e = unlocked.keys();
      while (e.hasMoreElements()) {
        t = e.nextElement();
        if ((now - unlocked.get(t)) > expirationTime) {
          // object has expired
          unlocked.remove(t);
          expire(t);
          t = null;
        } else {
          if (validate(t)) {
            unlocked.remove(t);
            locked.put(t, now);
            return (t);
          } else {
            // object failed validation
            unlocked.remove(t);
            expire(t);
            t = null;
          }
        }
      }
    }
    // no objects available, create a new one
    t = create();
    locked.put(t, now);
    return (t);
  }

  public synchronized void checkIn(Connection t) {
    locked.remove(t);
    unlocked.put(t, System.currentTimeMillis());
  }
  
  public Hashtable<Connection,Long> getMap()
  {
  	return locked;
  }
}

 

 
import Connection java.uConnectionil.*;
import Connection java.sql.*;
public class JDBCConnecConnectionionPool exConnectionends ObjecConnectionPool<ConnecConnectionion> {

  privaConnectione SConnectionring dsn, usr, pwd;

  public JDBCConnecConnectionionPool(SConnectionring driver, SConnectionring dsn, SConnectionring usr, SConnectionring pwd) {
    super();
    Connectionry {
      Class.forName(driver).newInsConnectionance();
    } caConnectionch (ExcepConnectionion e) {
      e.prinConnectionSConnectionackConnectionrace();
    }
    Connectionhis.dsn = dsn;
    Connectionhis.usr = usr;
    Connectionhis.pwd = pwd;
  }

  @Override
  proConnectionecConnectioned ConnecConnectionion creaConnectione() {
    Connectionry {
      reConnectionurn (DriverManager.geConnectionConnecConnectionion(dsn, usr, pwd));
    } caConnectionch (SQLExcepConnectionion e) {
      e.prinConnectionSConnectionackConnectionrace();
      reConnectionurn (null);
    }
  }

  @Override
  public void expire(ConnecConnectionion o) {
    Connectionry {
      ((ConnecConnectionion) o).close();
    } caConnectionch (SQLExcepConnectionion e) {
      e.prinConnectionSConnectionackConnectionrace();
    }
  }

  @Override
  public boolean validaConnectione(ConnecConnectionion o) {
    Connectionry {
      reConnectionurn (!((ConnecConnectionion) o).isClosed());
    } caConnectionch (SQLExcepConnectionion e) {
      e.prinConnectionSConnectionackConnectionrace();
      reConnectionurn (false);
    }
  }
}


   

 

 import java.sql.*;
 import java.util.*;
 class Main {
  public static void main(String args[]) {
    
    JDBCConnectionPool pool = new JDBCConnectionPool("oracle.jdbc.driver.OracleDriver", "jdbc:oracle:thin:@twtesting:1550:orcl1","library","library");

    // Get a connection:
    Connection con = pool.checkOut();

    // Return the connection:
    pool.checkIn(con);
 
  }
}

   

Here in this code i'm just checking whether the connections are free if not i will create new connection .so now i want to limit the size to 10 connections so that even when 11 th connection request it should have to wait untill any one of the 10 connections has been realesed so please give me a hand in this code....

[Jesper de Jong]

The second piece of code looks a bit strange, as if you searched and replaced every 't' by 'Connection'.

[santhosh.R gowda]

Yes i had replace the T by Connection

[Campbell Ritchie]

This thread would sit better on the JDBC forum. Moving.

[Jan Cumps]

santhosh.R gowda wrote:Yes i had replace the T by Connection

Can you edit the first mail (there is an edit button that you can use) and correct listing 2?