Question

我正在尝试调用REST端点，该端点为经过验证的城市地址返回JSON。在一次成功的通话中，我得到了这样的话：

{  
   "success":true,
   "results":[  
      {  
         "civicnumberid":123456,
         "civic_address_as_string":"123 Main Street, My City, My Municipality, My County",
         "esri_point":{  
            "x":12345.678,
            "y":54321.012
         }
      }
   ],
   "error":null
}

但是，如果我以服务无法处理的格式发送请求，我会退回这样的内容：

{  
   "success":false,
   "results":null,
   "error":{  
      "code":123,
      "message":"Invalid Civic Address. Valid Example: 123 Main St, My City...",
      "details":[  
         "The civic address submitted to the service contained an alphabetic character where a number was expected."
      ]
   }
}

请注意 “results”：null 。尝试使用JAX-RS 2.0和Jackson 2.5.1转换响应时：

ResponseObject response = client.target(url)
    .path(REST_REQUEST_CONTEXT)
    .queryParam("search_str", searchAddress)
    .request(MediaType.APPLICATION_JSON)
    .get(ResponseObject.class);

...它失败并显示“从输入流中读取实体时出错”。这是我当前的ObjectMapper设置：

    defaultObjectMapper.configure(SerializationFeature.WRAP_ROOT_VALUE, true)
   .configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true)
   .configure(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS, true)
   .configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true)
   .configure(DeserializationFeature.ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT, true)
   .configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true)

我的ResponseObject是一个JAXB对象：

public class ResponseObject
    implements Serializable
{

    private final static long serialVersionUID = 1L;
    protected Boolean success;
    @XmlElement(nillable = true)
    protected List<Result> results;
    @XmlElement(nillable = true)
    protected Error error;

可以优雅地处理 “results”：null ，还是应该与服务提供商合作返回空列表？

Answer 1

我认为空结果是问题我错了。 Error jaxb类型是使用以下模式类型定义的：

<xs:complexType name="Error">
    <xs:sequence>
        <xs:element minOccurs="0" name="code" type="xs:int" />
        <xs:element minOccurs="0" name="message" nillable="true" type="xs:string" />
        <xs:element minOccurs="0" name="details" nillable="true"
            type="q1:ArrayOfstring" xmlns:q1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" />
    </xs:sequence>
</xs:complexType>

...导致以下JAXB类型：

public class Error {

     protected Integer code;
     @XmlElement(nillable = true)
     protected String message;
     @XmlElement(nillable = true)
     protected ArrayOfstring details;

但是当我将架构更改为：

<xs:complexType name="Error">
    <xs:sequence>
        <xs:element minOccurs="0" name="code" type="xs:int" />
        <xs:element minOccurs="0" name="message" nillable="true" type="xs:string" />
        <!-- 
        <xs:element minOccurs="0" name="details" nillable="true"
            type="q1:ArrayOfstring" xmlns:q1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" />
             -->
        <xs:element minOccurs="0" name="details" maxOccurs="unbounded" nillable="true" type="xs:string" />
    </xs:sequence>
</xs:complexType>

...以下JAXB类型有效：

public class Error {

     private final static long serialVersionUID = 1L;
     protected Integer code;
     @XmlElement(nillable = true)
     protected String message;
     @XmlElement(nillable = true)
     protected List<String> details;

从空列表

1 个答案: