关于SpringCloud的微服务结构及微服务远程调用

@MapperScan("cn.itcast.order.mapper")
@SpringBootApplication
public class OrderApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class, args);
    }
    /**
     * 创建RestTemplate并注入Spring容器
     * @return
     */
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

@Service
public class OrderService {
    @Autowired
    private OrderMapper orderMapper;
    @Autowired
    private RestTemplate restTemplate;
    public Order queryOrderById(Long orderId) {
        // 1.查询订单
        Order order = orderMapper.findById(orderId);
        //2、利用RestTemplate发送http，查询用户
        //2.1 url路径
        String url = "http://localhost:8081/user/"+order.getUserId();
        //2。1 发送http请求，实现远程调用
        User user = restTemplate.getForObject(url,User.class);
        //3.封装user到Order
        order.setUser(user);
        // 4.返回
        return order;
    }
}