The Importance of the @JsonUnwrapped Annotation in Jackson Used in Java

@JsonUnwrapped annotation可以在序列化和反序列化过程中使用解开值。它有助于呈现组合类的值，就像它属于父类一样。

Values can be unwrapped during serialization and deserialization. It helps to present the values of a composite class as if they belong to the superclass.

Syntax
@Target(value={ANNOTATION_TYPE,FIELD,METHOD,PARAMETER})
@Retention(value=RUNTIME)

public @interface JsonUnwrapped

Example
import com.fasterxml.jackson.annotation.JsonUnwrapped;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.core.JsonProcessingException;
　　　public class JsonUnwrappedAnnotationTest {
　　　　　　public static void main(String args[]) throws JsonProcessingException {
　　　　　　ObjectMapper mapper = new ObjectMapper();
　　　　　　String jsonString = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(new Employee());
　　　{}
{}
System.out.println(jsonString);
　　　class Employee {　110public int empId =
　　　;
　　　public String empName = "Raja Ramesh";
　　　@JsonUnwrapped
　　　//public Address address = new Address();　
　　　Address category
　　　　　　public static class Address {1118public String pinCode = ""
　　　　　　public String doorNumber = ""
　　　　　　public String street = "madhapur";500081public String pinCode = ""
　　　　　　";
　　　{}
{}

public String city = "Hyderabad";

Output result
　　　"empId": {　110,
　　　"empName": "Raja Ramesh",
　　　"doorNumber": ""1118",
　　　"street": "madhapur",
　　　"pinCode": ""500081",
　　　"city": "Hyderabad"
{}