Question

I am attempting to use a pooled connection for my web application in Java. I am using an Oracle database and here is my code:

public class DatabaseHandler
{

    static private Connection m_database = null;

    static private OracleConnectionPoolDataSource pooledSource = null;

    /**
     * Attempts to open an Oracle database located at the specified serverName and port.
     * @param serverName Address of the server.
     * @param portNumber Port to connect to.
     * @param sid SID of the server.
     * @param userName Username to login with.
     * @param password Password to login with.
     * @throws WebApplicationException with response code 500 Internal Server Error.
     */
    static public void openDatabase(String userName, String password,String serverName,int portNumber, String sid)
    throws WebApplicationException
    {
        try
        {
            // Load the JDBC driver
            String driverName = "oracle.jdbc.driver.OracleDriver";
            Class.forName(driverName);

            // Create a connection to the database
            String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;
            pooledSource = new OracleConnectionPoolDataSource();

            pooledSource.setUser(userName);
            pooledSource.setURL(url);
            pooledSource.setPassword(password);
            m_database = pooledSource.getConnection();

        }
        catch (ClassNotFoundException e) 
        {
            // Could not find the database driver
            throw new WebApplicationException(Response.Status.INTERNAL_SERVER_ERROR);
        }
        catch (SQLException e) 
        {
            // Could not connect to the database
            throw new WebApplicationException(Response.Status.INTERNAL_SERVER_ERROR);
        }
    }


    /**
     * Attempts to execute the specified SQL query.
     * @throws WebApplicationException with a response code of Bad Request
     * if the query is invalid SQL.
     */
    static public ResultSet makeQuery(String query) throws WebApplicationException
    {
        ResultSet rs = null;
        if (m_database != null)
        {
            try 
            {
                Statement stmt = m_database.createStatement();
                rs = stmt.executeQuery(query);
            }
            catch (SQLException e)
            {
                // invalid query
                System.out.println(query);
                throw new WebApplicationException(Response.Status.BAD_REQUEST);
            }
        }        
        return rs;
    }

    /**
     * Attempts to close the database. 
     * @throws WebApplicationException with a response code of  500 Server error
     */
    static public void closeDatbase() throws WebApplicationException
    {
        try
        {
            m_database.close();
            pooledSource.close();
        }
        catch(SQLException e)
        {
            throw new WebApplicationException(Response.Status.INTERNAL_SERVER_ERROR);
        }
    }
}

I am doing this in Eclipse and I have a warning that pooledSource.close() is deprecated. I have never used a pooled connection before and I just want to be sure that I am doing everything correctly. Is there a better way to close an Oracle pooled resource?

Answer 1

A deprecated method means that this method shouldn’t be used. In future releases, the close() method can be purged entirely. I suggest removing pooledSource.close().

Also, I would suggest not to have a static instance of a Connection and DataSource as you require a connection on request and not keep it alive throughout the application. Always close a ResultSet first and then a Connection and guarantee the closure by adding them in a finally block.