Example: Obtain an initial context before binding UDBDataSource

// Import the required packages. There is no
// driver-specific code needed in runtime 
// applications.
import java.sql.*;
import javax.sql.*;
import javax.naming.*;

public class UDBDataSourceUse
{
    public static void main(java.lang.String[] args) 
    throws Exception
    {
        // Retrieve a JNDI context. The context serves
        // as the root for where objects are bound or
        // found in JNDI.
        Context ctx = new InitialContext();

        // Retrieve the bound UDBDataSource object using the 
        // name with which it was previously bound. At runtime,
        // only the DataSource interface is used, so there 
        // is no need to convert the object to the UDBDataSource
        // implementation class. (There is no need to know what
        // the implementation class is. The logical JNDI name is 
        // only required).
        DataSource ds = (DataSource) ctx.lookup("SimpleDS");
        

        // Once the DataSource is obtained, it can be used to establish
        // a connection. This Connection object is the same type
        // of object that is returned if the DriverManager approach
        // to establishing connection is used. Thus, so everything from
        // this point forward is exactly like any other JDBC 
        // application.
        Connection connection = ds.getConnection();

        // The connection can be used to create Statement objects and
        // update the database or process queries as follows.
        Statement statement = connection.createStatement();
        ResultSet rs = statement.executeQuery("select * from qsys2.sysprocs");
        while (rs.next()) {
            System.out.println(rs.getString(1) + "." + rs.getString(2));
        }
        
        // The connection is closed before the application ends.
        connection.close();
    }
}