Encapsulate State for the Command Pattern with a Memento

The purpose of the Memento Pattern is to encapsulate state.

class Memento {
   private State state;
 
   public Memento(State stateToSave) { state = stateToSave; }
   public State useState() { return state; }
}

When I use the Command Pattern, I combine it with the memento pattern.

Here is the interface that I use when implementing the command pattern.

/**
 * An Interface for a Command Object 
 * see Command Pattern [GOF:233]
 * @author martin.spamer
 * @version 0.1 - 14:08:58
 **/
public interface CommandInterface
  {
  /**
   *  An Interface for a Command Object 
   *  see Command Pattern [GOF:233]
   *  @param java.util.Properties
   *  @return java.util.Properties
   */  
  public java.util.Properties execute( java.util.Properties properties)
    throws CommandException ;
  }