Java 使用父属性值对jackson进行多态反序列化
我有一个json,如下所示:Java 使用父属性值对jackson进行多态反序列化,java,json,jackson,jackson-databind,jackson2,Java,Json,Jackson,Jackson Databind,Jackson2,我有一个json,如下所示: { "transformationRules": [ { "targetFieldName": "pageUrlNumber", "inputPath": "$.metadata.pageUrl", "rules": [
{
"transformationRules": [
{
"targetFieldName": "pageUrlNumber",
"inputPath": "$.metadata.pageUrl",
"rules": [
{
"name": "regex",
"regexPattern": "\\d+",
"regexTransformType": "extract",
"order":2
}
]
},
{
"targetFieldName": "categories",
"inputPath": "$.attributes[0].productInfo.breadCrumbs",
"rules": [
{
"name": "transform"
}
]
}
]
}
规则
数组具有不同类的json
我希望根据名称的值(即regex,transform)将上述json转换为它们的POJO。我尝试了以下代码
Rule.java
@NoArgsConstructor
@Data
@JsonTypeInfo(
use = JsonTypeInfo.Id.NAME,
include = JsonTypeInfo.As.EXTERNAL_PROPERTY,
property = "name")
@JsonSubTypes({
@JsonSubTypes.Type(value = RegexRule.class, name = "regex"),
@JsonSubTypes.Type(value = Transform.class, name = "transform"),
})
public abstract class Rule {
@JsonProperty("name")
private String name;
@JsonProperty("order")
private int order = 1;
protected Rule(String name, int order) {
this.name = name;
this.order = order;
}
}
RegexRule.java
@NoArgsConstructor
@Data
public class RegexRule extends Rule{
@JsonProperty("regexPattern")
private String regexPattern;
@JsonProperty("regexTransformType")
private String regexTransformType;
@JsonProperty("replacementValue")
private String replacementValue = "";
@JsonProperty("regexGroupNumber")
private int regexGroupNumber = 0;
public RegexRule(String name, int order, String regexPattern, String regexTransformType, String replacementValue, int regexGroupNumber) {
super(name, order);
this.regexGroupNumber = regexGroupNumber;
this.regexPattern = regexPattern;
this.regexTransformType = regexTransformType;
this.replacementValue = replacementValue;
}
}
Transform.java
@NoArgsConstructor
@Data
public class Transform extends Rule{
public Transform(String name, int order) {
super(name, order);
}
}
Main.java
for(TransformationRule transformationRule: getTransformationRules()){
for(Rule rule:transformationRule.getRules()){
System.out.println(rule.getName());
}
}
输出:
null
null
在我的主函数中,当我将json反序列化到POJO时,我得到的名称为null。相反,我应该将regex
和transform
作为输出
我在这里犯了什么错误?我需要一个工厂方法的名称在这里听起来是错误的,我很惊讶如果它真的起作用,那就意味着:
{
"name": "regex", // This is the *external* property, one level up
{ // this is the Rule
"order": 2,
...
}
}
试一试
As.PROPERTY
- 您可以从POJO中删除
,因为它被视为只有Jackson才能正确反序列化的元数据。记住Rule#name
与RegexRule的rule.getName()=“regex”
规则实例相同
- 您可以从POJO中删除
As.现有财产
- 将按照您的预期填充字段,但在规模上可能会有稍差的性能(仅当应用程序持续执行此操作时才有关系)
- 有关另一个示例,请参见