Jackson YAML多态序列化：禁用原生类型ID标签以获得纯净输出

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator;
import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;
import com.google.common.collect.ImmutableList; // 假设引入了Guava
import lombok.Value; // 假设引入了Lombok

import java.util.List;
import static java.util.Objects.requireNonNull;

// 定义多态接口及其子类
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type")
@JsonSubTypes({
    @JsonSubTypes.Type(value = Car.class, name = "car"),
    @JsonSubTypes.Type(value = Truck.class, name = "truck")
})
public interface Vehicle {
    String getName();
}

@Value
public static class Car implements Vehicle {
    String name;
    String type = "car"; // 类型属性

    @JsonCreator
    public Car(@JsonProperty("name") final String name) {
        this.name = requireNonNull(name);
    }
}

@Value
public static class Truck implements Vehicle {
    String name;
    String type = "truck"; // 类型属性

    @JsonCreator
    public Truck(@JsonProperty("name") final String name) {
        this.name = requireNonNull(name);
    }
}

@Value
public static class Vehicles {
    List<Vehicle> vehicles;

    @JsonCreator
    public Vehicles(@JsonProperty("vehicles") final List<Vehicle> vehicles) {
        this.vehicles = requireNonNull(vehicles);
    }
}

public class SerializationExample {
    public static void main(String[] args) throws JsonProcessingException {
        ObjectMapper jsonMapper = new ObjectMapper();
        // 初始YAML Mapper配置，未禁用原生类型ID
        ObjectMapper yamlMapper = YAMLMapper.builder()
            .disable(YAMLGenerator.Feature.WRITE_DOC_START_MARKER)
            .build();

        final Vehicles vehicles = new Vehicles(ImmutableList.of(new Car("Dodge"), new Truck("Scania")));

        System.out.println("--- JSON Output ---");
        final String json = jsonMapper.writerWithDefaultPrettyPrinter().writeValueAsString(vehicles);
        System.out.println(json);

        System.out.println("\n--- YAML Output (Before Fix) ---");
        final String yaml = yamlMapper.writerWithDefaultPrettyPrinter().writeValueAsString(vehicles);
        System.out.println(yaml);
    }
}

--- JSON Output ---
{
  "vehicles" : [ {
    "name" : "Dodge",
    "type" : "car"
  }, {
    "name" : "Scania",
    "type" : "truck"
  } ]
}

--- YAML Output (Before Fix) ---
vehicles:
- !<car>
  name: "Dodge"
  type: "car"
- !<truck>
  name: "Scania"
  type: "truck"

import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator;
import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;
import com.fasterxml.jackson.databind.ObjectMapper;

// ... (其他类定义保持不变)

public class SerializationExampleFixed {
    public static void main(String[] args) throws JsonProcessingException {
        ObjectMapper jsonMapper = new ObjectMapper();
        // 关键修改：禁用YAMLGenerator.Feature.USE_NATIVE_TYPE_ID
        ObjectMapper yamlMapper = YAMLMapper.builder()
            .disable(YAMLGenerator.Feature.WRITE_DOC_START_MARKER) // 可选：禁用文档起始标记
            .disable(YAMLGenerator.Feature.USE_NATIVE_TYPE_ID)     // 关键：禁用原生类型ID
            .build();

        final Vehicles vehicles = new Vehicles(ImmutableList.of(new Car("Dodge"), new Truck("Scania")));

        System.out.println("--- JSON Output ---");
        final String json = jsonMapper.writerWithDefaultPrettyPrinter().writeValueAsString(vehicles);
        System.out.println(json);

        System.out.println("\n--- YAML Output (After Fix) ---");
        final String yaml = yamlMapper.writerWithDefaultPrettyPrinter().writeValueAsString(vehicles);
        System.out.println(yaml);
    }
}

--- JSON Output ---
{
  "vehicles" : [ {
    "name" : "Dodge",
    "type" : "car"
  }, {
    "name" : "Scania",
    "type" : "truck"
  } ]
}

--- YAML Output (After Fix) ---
vehicles:
- name: "Dodge"
  type: "car"
- name: "Scania"
  type: "truck"