001package headfirst.command.undo; 002 003public class DimmerLightOffCommand implements Command { 004 Light light; 005 int prevLevel; 006 007 public DimmerLightOffCommand(Light light) { 008 this.light = light; 009 prevLevel = 100; 010 } 011 012 public void execute() { 013 prevLevel = light.getLevel(); 014 light.off(); 015 } 016 017 public void undo() { 018 light.dim(prevLevel); 019 } 020}