Who has read J2EE tutorial, please explain to me.

Question

The Converter bean example in J2EE tutorial....
Why ConverterHome can refer to Converter without importing Converter first?

Answer 1

* Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
* Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
import javax.ejb.EJBObject;
import java.rmi.RemoteException;
import java.math.*;
public interface Converter extends EJBObject {
public BigDecimal dollarToYen(BigDecimal dollars) throws RemoteException;
public BigDecimal yenToEuro(BigDecimal yen) throws RemoteException;
import java.io.Serializable;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
import javax.ejb.EJBHome;
public interface ConverterHome extends EJBHome {
Converter create() throws RemoteException, CreateException;
The above code is excerpt from the tutorial sample files.
The problem is that these two classes are not in the same source file. They cannot be since there can be one and only one public class in a source file.
So how come ConverterHome can refer to Converter without import?