杰克逊xml和json根元素

Question

我有一个服务，它返回JSON和XML格式的对象。

http://localhost:8091/apiN/xml/2

XML结果

<restObjectList> 
    <restObjectList> 
     <restObjectList> 
      <timestamp>2017-06-19 17:01:01</timestamp> 
      <title>Rest object</title> 
      <fullText>This is the full text. ID: 1</fullText> 
      <id>1</id> 
      <value>0.1412789210135622</value> 
     </restObjectList> 
     <restObjectList> 
      <timestamp>2017-06-19 17:01:01</timestamp> 
      <title>Rest object</title> 
      <fullText>This is the full text. ID: 2</fullText> 
      <id>2</id> 
      <value>0.9886539664938628</value> 
     </restObjectList> 
    </restObjectList> 
</restObjectList> 

http://localhost:8091/apiN/2

JSON结果

{ 
    "restObjectList": [ 
     { 
      "timestamp": "2017-06-19 17:01:01", 
      "title": "Rest object", 
      "fullText": "This is the full text. ID: 1", 
      "id": 1, 
      "value": 0.1412789210135622 
     }, 
     { 
      "timestamp": "2017-06-19 17:01:01", 
      "title": "Rest object", 
      "fullText": "This is the full text. ID: 2", 
      "id": 2, 
      "value": 0.9886539664938628 
     } 
    ] 
} 

结果我想收到

XML

<restObjectList> 
    <restObject> 
     <timestamp>2017-06-19 17:01:01</timestamp> 
     <title>Rest object</title> 
     <fullText>This is the full text. ID: 1</fullText> 
     <id>1</id> 
     <value>0.1412789210135622</value> 
    </restObject> 
    <restObject> 
     <timestamp>2017-06-19 17:01:01</timestamp> 
     <title>Rest object</title> 
     <fullText>This is the full text. ID: 2</fullText> 
     <id>2</id> 
     <value>0.9886539664938628</value> 
    </restObject> 
</restObjectList> 

JSON

{ 
    "restObjectList": [{ 
     "restObject": { 
      "timestamp": "2017-06-19 17:01:01", 
      "title": "Rest object", 
      "fullText": "This is the full text. ID: 1", 
      "id": 1, 
      "value": 0.1412789210135622 
     } 
    }, { 
     "restObject": { 
      "timestamp": "2017-06-19 17:01:01", 
      "title": "Rest object", 
      "fullText": "This is the full text. ID: 2", 
      "id": 2, 
      "value": 0.9886539664938628 
     } 
    }] 
} 

如何包装restObject对JSON和XML和XML解决数据restObjectList因为这个标签在不同层次重复。

我的代码

RestObject

@JsonRootName(value = "restObject") 
@XmlRootElement(name = "restObject") 
public class RestObject implements Serializable { 

    private LocalDateTime timestamp; 
    private String title; 
    private String fullText; 
    private Long id; 
    private Double value; 

    //Getters, setters 
} 

RestObjectList

@JsonRootName(value = "restObjectList") 
@XmlSeeAlso({RestObject.class}) 
public class RestObjectList { 

    private List<RestObject> restObjectList; 

    //Getter and setter 
} 

JacksonConfig

@Configuration 
public class JacksonConfig { 

    @Bean 
    public ObjectMapper objectMapper(Jackson2ObjectMapperBuilder builder) { 
     ObjectMapper objectMapper = builder.createXmlMapper(true).build(); 
     objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);//Use custom date-time format. 
     objectMapper.configure(SerializationFeature.WRAP_ROOT_VALUE, false); 
     objectMapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, false); 
     return objectMapper; 
    } 

    @Bean 
    public ObjectMapper objectMapper() { 
     ObjectMapper objectMapper = new ObjectMapper(); 
     objectMapper.enable(SerializationFeature.WRAP_ROOT_VALUE); 
     objectMapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE); 
     return objectMapper; 
    } 
} 

Answer 1

JSON和XML结构不等效。在XML中，您需要一个RestObject的列表，在JSON中，您需要一个列表，其元素在另一个对象中包含RestObject的实例。这不是用简单的Jackson注释可以得到的，只需要一个用于JSON序列化的自定义序列化程序。首先，获得所需的XML格式很简单：

class RestObject implements Serializable { 
    private LocalDateTime timestamp; 
    private String title; 
    private String fullText; 
    private Long id; 
    private Double value; 
} 

@JsonRootName("restObjectList") 
class RestObjectList { 
    @JacksonXmlProperty(localName = "restObject") 
    @JacksonXmlElementWrapper(useWrapping = false) 
    private List<RestObject> restObjectList; 
} 

如果你绝对要包装的每个元素在JSON数组中，你需要自定义序列例如

class RestObjectSerializer extends JsonSerializer<RestObject> { 
    @Override 
    public void serialize(RestObject value, JsonGenerator gen, SerializerProvider serializers) throws 
      IOException { 
     gen.writeStartObject(); 
     gen.writeObjectFieldStart("restObject"); 
     gen.writeObjectField("timeStamp", value.getTimestamp()); 
     gen.writeStringField("title", value.getTitle()); 
     // other fields 
     gen.writeEndObject(); 
     gen.writeEndObject(); 
    } 
} 

而且只与序列化JSON所以它不会干扰序列化到XML的ObjectMapper注册：

ObjectMapper mapper = new ObjectMapper(); 
SimpleModule module = new SimpleModule("MyModule"); 
module.addSerializer(RestObject.class, new RestObjectSerializer()); 
mapper.registerModule(module);