/*
 * This example is from the book "Java Enterprise in a Nutshell".
 * Copyright (c) 1999 by O'Reilly & Associates.  
 * You may distribute this source code for non-commercial purposes only.
 * You may study, modify, and use this example for any purpose, as long as
 * this notice is retained.  Note that this example is provided "as is",
 * WITHOUT WARRANTY of any kind either expressed or implied.
 */

import java.util.Vector;
import javax.naming.*;

public class list implements Command {
  public void execute(Context c, Vector v) throws CommandException {
        
    String name = "";
        
    // An empty string is OK for a list operation as it means
    // list children of the current context.
    if (!(v.isEmpty()))
      name = (String)v.firstElement();
        
    // Check for current context; throw an exception if there isn’t one
    if (NamingShell.getCurrentContext() == null)
      throw new CommandException(new Exception(), 
        "Error: no current context.");

    // Call list() and then loop through the results, printing the names
    // and class names of the children
    try {
      NamingEnumeration enum = c.list(name);                
      while (enum.hasMore()) {
        NameClassPair ncPair = (NameClassPair)enum.next();
        System.out.print(ncPair.getName() + " (type ");
        System.out.println(ncPair.getClassName() + ")");
      }
    }
    catch (NamingException e) {
      throw new CommandException(e, "Couldn't list " + name);
    }
  }

  public void help() { System.out.println("Usage: list [name]"); }
}