【SpringCloud】01-远程调用

1. RestTemplate

• 1. 注册Bean

@SpringBootApplication
public class CartServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(CartServiceApplication.class, args);
        System.out.println("cart启动成功");
    }

    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

}

• 2. 在代码中引入Bean

// 推荐使用构造函数注入, 使用lombook的@RequiredArgsConstructor进行注入
    private final RestTemplate restTemplate;

• 3. 远程调用

// 1.获取商品id
        Set<Long> itemIds = vos.stream().map(CartVO::getItemId).collect(Collectors.toSet());
        // 2.查询商品
        ResponseEntity<List<ItemDTO>> response = restTemplate.exchange(
                "http://localhost:8081/items?ids={ids}",
                HttpMethod.GET,
                null,
                new ParameterizedTypeReference<List<ItemDTO>>() {
                },
                Map.of("ids", CollUtil.join(itemIds, ","))
        );
        if (!response.getStatusCode().is2xxSuccessful()) {
            return;
        }
        List<ItemDTO> items = response.getBody();