简易版策略模式.去除if.else

场景:

        Order order = new Order();
        if (order.getType() == 1) {
            handle1(order);
        } else if (order.getType() == 2) {
            handle2(order);
        } else if (order.getType() == 3) {
            handle3(order);
        }

实现(类似于简易版的策略模式):

private final static ImmutableMap<Integer, Function<Order,String>> ORDER_TYPE_MAP =
ImmutableMap.<Integer, Function<Order,String>>builder()
            .put(1, order->handle1(order))
            .put(2, order->handle2(order))
            .build();

ORDER_TYPE_MAP.get(order.getType() ).accept(new Order());