import java.sql.*;
import com.ibm.db2.jcc.*;
import java.util.ArrayList;

public class DBAccess {
    
    private static DBAccess _instance = null;
    private static String dbName = "testdb";
    private static String serverName = "192.168.1.1";
    private static String login  = "login";
    private static String passw  = "pasword";
    private DB2PooledConnection pool = null;

    
    private DBAccess(){
        try{

            DB2ConnectionPoolDataSource db2pc = new DB2ConnectionPoolDataSource();
            db2pc.setDatabaseName(dbName);
            db2pc.setPortNumber( 50000 );
            db2pc.setServerName(serverName);
            db2pc.setUser(login);
            db2pc.setPassword(passw);
            pool = (DB2PooledConnection)db2pc.getPooledConnection();
            //con = DriverManager.getConnection(dbpath,login,passw);

        }
        catch (Exception e){}
    }
    
    public static DBAccess getInstance(){
        if (_instance == null)
        {
            try{
                Class.forName("com.ibm.db2.jcc.DB2Driver");                
            }
            catch(Exception e) {return null;}

            _instance = new DBAccess();
            return _instance;
        }
        else return _instance;
    }

    public BuisenessObject[] getBuisenessObjects(){
        CallableStatement cstmt = null;
		ResultSet rs = null;
        try {
            Connection con = pool.getConnection();
            PreparedStatement com = con.prepareStatement("SELECT ...");
            //Ну и понеслась
	    }
	    catch (Exception e) {
            e.printStackTrace();
            return null;
	    }

	   	finally {
            //все подчистить
        }
    }

    public AnotherBuisenessObject[] getAnotherBuisenessObject(){
        try {
            String sql = "select ... ";
            Connection con = pool.getConnection();
            PreparedStatement com = con.prepareStatement(sql);
            //Ну и т.д.
	    }
	    catch (Exception e) {
            e.printStackTrace();
            return null;
	    }

	   	finally {
            //все подчистить
	    }
    }
}