Json 无法在 Spring 中反序列化实例错误

Question

我正在尝试发送一个 json 长列表并从数据库中获取记录。

我的控制器是：

@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);
}
}

客户端类为：

@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 在邮递员中测试这项服务：

{ "ids"： [1,7,8] }

但是我收到此错误：

{
"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 tokenn 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 tokenn at [Source: java.io.PushbackInputStream@3cb8b584; line: 1, column: 1]",
"path": "/api/v1/customer/customers/search",
"errors": []
}

问题出在哪里？您是否在这里看到任何问题，或者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]请求，而不是{"ids": [1,7,8]}。

JSON 将转换为具有下一个格式的请求正文。

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()