21.8 The MudPerson Class

Example 21-7 shows the MudPerson class. This is the simplest of the remote objects in the MUD system. It implements the two remote methods defined by the RemoteMudPerson interface and also defines a few nonremote methods used by the MudClient class of Example 21-8. The remote methods are quite simple: one simply returns a description string to the caller, and the other writes a message to a stream where the user can see it.

Example 21-7. MudPerson.java

package je3.rmi;
import java.rmi.*;
import java.rmi.server.*;
import java.io.*;
import je3.rmi.Mud.*;

/**
 * This is the simplest of the remote objects that we implement for the MUD.
 * It maintains only a little bit of state, and has only two exported
 * methods 
 **/
public class MudPerson extends UnicastRemoteObject implements RemoteMudPerson {
    String name;             // The name of the person 
    String description;      // The person's description
    PrintWriter tellStream;  // Where to send messages we receive
    
    public MudPerson(String n, String d, PrintWriter out)
        throws RemoteException
    {
        name = n;
        description = d;
        tellStream = out;
    }
    
    /** Return the person's name.  Not a remote method */
    public String getName( ) { return name; }
    
    /** Set the person's name.  Not a remote method */
    public void setName(String n) { name = n; }
    
    /** Set the person's description.  Not a remote method */
    public void setDescription(String d) { description = d; }
    
    /** Set the stream that messages to us should be written to. Not remote. */
    public void setTellStream(PrintWriter out) { tellStream = out; }
    
    /** A remote method that returns this person's description */
    public String getDescription( ) throws RemoteException {
        return description;
    }
    
    /** 
     * A remote method that delivers a message to the person.
     * I.e. it delivers a message to the user controlling the "person"
     **/
    public void tell(String message) throws RemoteException {
        tellStream.println(message);
        tellStream.flush( );
    }
}