java - Spring中Json无法反序列化实例错误

Question

我正在尝试发送一个 json 长列表并从数据库中获取记录。

我的 Controller 是:

@Api(tags = Endpoint.RESOURCE_customer, description = "customer Resource")
@RestController
@RequestMapping(produces = MediaType.APPLICATION_JSON_VALUE,consumes = MediaType.APPLICATION_JSON_VALUE)
@ResponseStatus(HttpStatus.OK)
public class CustomerResourceController {

    private final customerService customerService;


    public CustomerResourceController(customerService customerService) {

        this.customerService = customerService;
    }

    @ApiOperation(
            value = "Return customer",
            response = customerDto.class, responseContainer="List"
    )
    @PostMapping(value = Endpoint.RRESOURCE_customer_ID)
    public List<customerDto> getCustomersByIds(@RequestBody List<Long> ids) {
        return customerService.findcustomerIds(ids);
    }

}

客户端类是:

@Headers("Content-Type: " + MediaType.APPLICATION_JSON_VALUE)
public interface CustomerClient {

@RequestLine("POST /customer/customers/search")
    List<LocGrpDto> getCustomersByIds(@RequestBody @Validated List<Long> ids);
}

我用 JSON 在 postman 中测试了这项服务:

{ "ids": [1,7,8] }

但我收到此错误:

{
    "timestamp": "2018-10-05T13:29:57.645+0000",
    "status": 400,
    "error": "Bad Request",
    "message": "Could not read document: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token\n at [Source: java.io.PushbackInputStream@3cb8b584; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token\n at [Source: java.io.PushbackInputStream@3cb8b584; line: 1, column: 1]",
    "path": "/api/v1/customer/customers/search",
    "errors": []
}

有什么问题吗？您在这里看到任何问题吗？或者这可能是由于我的服务类或 dto 类引起的？

Answer 1

尝试使用有效负载 [1,7,8] 进行请求，而不是 {"ids": [1,7,8]}。

您的 JSON 将转换为具有下一种格式的请求正文。

class Body {

    private List<Long> ids;

    // constructor, getters and setters 

}

对于 REST 客户端，您可以查看 RestTemplate。

RestTemplate template;
List<Long> ids;
List<CustomerDto> = template.exchange(
            "/customer/customers/search",
            HttpMethod.POST,
            new HttpEntity<>(ids),
            new ParameterizedTypeReference<List<CustomerDto>>() {}).getBody()