import java.io.*;

// in implementation, you do not have to extend this as in Java RMI. 
// in your design, however, you can do so.
// it is assumed that this is not directly called but as in:
//
//   java yourRMI ZipCodeServerImpl registryhost resigstryport servicename
//
// therefore it does not contain main: new object creation, binding etc. is 
// done via your RMI.

public class ZipCodeServerImpl
    implements ZipCodeServer
{
    ZipCodeList l;
	
    // this is a constructor.
    public ZipCodeServerImpl()
    {
	l=null;
    }

    // when this is called, marshalled data
    // should be sent to this remote object,
    // and reconstructed.
    public void initialise(ZipCodeList newlist)
    {
	l=newlist;
    }

    // basic function: gets a city name, returns the zip code.
    public String find(String request)
    {
	// search the list.
	ZipCodeList temp = l;
	while (temp != null && !temp.city.equals(request))
	    temp = temp.next;

	// the result is either null or we found the match.
	if (temp==null)
	    return null;
	else
	    return temp.ZipCode;
    }

    // this very short method should send the marshalled 
    // whole list to the local site.
    public ZipCodeList findAll()
    {
	return l;
    }

    // this method does printing in the remote site, not locally.
    public void printAll() 
    {
	ZipCodeList temp=l;
	while (temp !=null)            
	    {
		System.out.println
		    ("city: "+temp.city+", "+
		     "code: "+temp.ZipCode+"\n");        
		temp = temp.next;                        
	    }
    }
}