文字冒险问题

我正在做一个简单的文字冒险项目。但是，当我运行代码时，当我尝试两次输入向右/向左/向前/向后时，它将不起作用。它只是停止。另外，当我向前执行然后向左执行时，程序将进入我的故障保护模式。不仅如此，故障保护也不起作用。我输入左键，故障保护继续。我该如何解决这些问题？

if(direction.equals("right") || direction.equals("Right"))
  {
    x++;
    System.out.println("You walk to the right.");
    direction = key.next();
  }

  if (direction.equals("left") || direction.equals("Left"))
  {
    x--;
    System.out.println("You walk to the left.");
    direction = key.next();
  }

  if (direction.equals("forward") || direction.equals("Forward"))
  {
    y++;
    System.out.println("You walk Forward.");
    direction = key.next();
  }

  if (direction.equals("backwards") || direction.equals("Backwards"))
  {
    y--;
    System.out.println("You walk backwards.");
    direction = key.next();
  }

  do{
    System.out.print("Sorry, you can't do that.  Try again:");
    direction = key.next();
  }while(!direction.equals("right") || !direction.equals("Right") || !direction.equals("left") || !direction.equals("Left") || !direction.equals("forward") || !direction.equals("Forward") || !direction.equals("backwards") || !direction.equals("Backwards") || !direction.equals("c"));