I am using Jackson to serialize my Java POJO classes. In addition to
fields, I have in Java POJO, I would like to add some additional
information in JSON I am writing my own custom `CustomClassSerializer`. If
I use this class and register to `ObjectMapper` then I get the error:
```
Exception in thread "main"
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Type id
handling not implemented for type org.acme.Tiger (by serializer of type
org.acme.CustomModule$CustomClassSerializer)
```
I am unable to understand what might be going wrong here. If I remove the
custom registered model then everything works perfectly.
Can someone please let me know what may be the cause of this issue? I am
currently using Jackson 2.13.2 latest version dependencies: `jackson-core,
jackson-databind, jackson-annotations, jackson-datatype-jdk8`:
Following is the sample code:
```
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import lombok.*;
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include =
JsonTypeInfo.As.PROPERTY, visible = true, property = "type")
@JsonSubTypes({@JsonSubTypes.Type(value = Bat.class, name = "Bat"),
@JsonSubTypes.Type(value = Tiger.class, name = "Tiger")})
@JsonInclude(JsonInclude.Include.NON_NULL)
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Animal {
private String type;
private String name;
}
```
```
@JsonInclude(JsonInclude.Include.NON_NULL)
@EqualsAndHashCode(callSuper = true)
@ToString(callSuper = true)
@Data
@NoArgsConstructor
@AllArgsConstructor
@JsonTypeName("Tiger")
public class Tiger extends Animal {
private String livingType;
private String foundIn;
}
```
```
@JsonInclude(JsonInclude.Include.NON_NULL)
@EqualsAndHashCode(callSuper = true)
@ToString(callSuper = true)
@Data
@NoArgsConstructor
@AllArgsConstructor
@JsonTypeName("Bat")
public class Bat extends Animal{
private String livingType;
private String foundIn;
}
```
```
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.BeanDescription;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.BeanSerializerFactory;
import java.io.IOException;
public class CustomModule extends SimpleModule {
public CustomModule() {
addSerializer(Tiger.class, new CustomClassSerializer());
}
private static class CustomClassSerializer extends JsonSerializer {
@Override
public void serialize(Object value, JsonGenerator jgen,
SerializerProvider provider) throws IOException {
jgen.writeStartObject();
jgen.writeObjectField("my_extra_field1", "some data");
jgen.writeObjectField("my_extra_field2", "some more data");
JavaType javaType = provider.constructType(Tiger.class);
BeanDescription beanDesc =
provider.getConfig().introspect(javaType);
JsonSerializer<Object> serializer =
BeanSerializerFactory.instance.createSerializer(provider, javaType);
serializer.unwrappingSerializer(null).serialize(value, jgen,
provider);
jgen.writeEndObject();
}
}
}
```
```
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class TestMain {
public static void main(String[] args) throws JsonProcessingException {
final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
objectMapper.registerModule(new CustomModule());
Tiger tiger = new Tiger();
tiger.setType("Tiger");
tiger.setName("Shera");
tiger.setFoundIn("Ground");
tiger.setLivingType("Tree");
System.out.println(objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(tiger));
}
}
```
I would like to know what are the causes for the above-mentioned exception.
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