switch.java~9~

《深入浅出设计模式》的完整源代码

package testcommand;
class Switch{
  private Command UpCommand, DownCommand;
  public Switch(Command Up, Command Down) {
    UpCommand = Up; // concrete Command registers itself with the invoker
    DownCommand = Down;
  }
  public void flipUp () { // invoker calls back concrete Command, which executes the Command on the receiver
    UpCommand.execute ();
  }
  public void flipDown () {
    DownCommand.execute ();
  }
}