通用抽象类的java自定义反序列化
我在尝试反序列化以下类时遇到问题:
public class MetricValuesDto {
private Map<MetricType, MetricValueDto<?>> metricValues;
public MetricValuesDto() {
}
public MetricValuesDto(Map<MetricType, MetricValueDto<?>> metricValues) {
this.metricValues = metricValues;
}
public Map<MetricType, MetricValueDto<?>> getMetricValues() {
return metricValues;
}
public void setMetricValues(Map<MetricType, MetricValueDto<?>> metricValues) {
this.metricValues = metricValues;
}
}
我的通用抽象类:
public abstract class MetricValueDto<T> {
private T value;
private MetricTrend trend;
public MetricValueDto(T value, MetricTrend trend) {
this.value = value;
this.trend = trend;
}
public T getValue() {
return value;
}
public void setValue(T value) {
this.value = value;
}
public MetricTrend getTrend() {
return trend;
}
public void setTrend(MetricTrend trend) {
this.trend = trend;
}
}
我有两个具体的类来实现MetricValueDto
:
IntMetricValueDto:
public class IntMetricValueDto extends MetricValueDto<Integer> {
public IntMetricValueDto(Integer value, MetricTrend trend) {
super(value, trend);
}
}
FloatMetricValueDto:
public class FloatMetricValueDto extends MetricValueDto<Float> {
public FloatMetricValueDto(Float value, MetricTrend trend) {
super(value, trend);
}
}
你知道什么是反序列化MetricValueDto的正确策略吗?这样我就可以通过ObjectMapper或RestTemplate解析它了?每当我跑步时:
restTemplate.exchange("myEndpoint", HttpMethod.GET, entity, DataCollectionEventDto.class);
我明白了
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of com.resson.dto.MetricValueDto: abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information
DataCollectionEventTo:
public class DataCollectionEventDto {
private List<MapLayerDto> mapLayers;
@JsonUnwrapped
private MetricValuesDto metricValues;
public List<MapLayerDto> getMapLayers() {
return mapLayers;
}
public void setMapLayers(List<MapLayerDto> mapLayers) {
this.mapLayers = mapLayers;
}
public MetricValuesDto getMetricValues() {
return metricValues;
}
public void setMetricValues(MetricValuesDto metricValues) {
this.metricValues = metricValues;
}
@Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
}
我基本上尝试过网络上的所有东西,但都没能成功;任何建议都会有帮助
# 1 楼答案
而
JsonTypeInfo
可以工作,并在响应中添加了特定于实现的细节,这可能会给API客户机带来混乱我最终实现了一个自定义StdDeserializer:
代码最终比
JsonTypeInfo
更复杂,但API客户端不知道具体实现的细节# 2 楼答案
使用JsonSubTypes注释和JsonTypeInfo来指示子类型。属性JsonTypeInfo用于区分不同的子类