尝试将JSON字符串转换为JavaPOJO时遇到一个奇怪的问题

Question

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.9.8</version>
        </dependency>

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException：无法识别的字段“ID”（类com.optimight.prakash.general.employee）未标记为可忽略（0个已知属性:])，位于[源：（字符串）“{”ID“：1,”名称“：”Lokesh Gupta“,”年龄“：34,”位置“：”印度“}”；行：1,列：8]（通过引用链：com.optimight.prakash.general.employee[“id”]）在com.fasterxml.jackson.databind.exc.unrecognizedpropertyexception.from（unrecognizedpropertyexception.java：61）在com.fasterxml.jackson.databind.deserializationcontext.handleunknownproperty（deserializationcontext.java:823)在jectMapper.java:3004)在com.optimight.prakash.general.jsonToJavaPojo.main(jsonToJavaPojo.java:18)

在就业课上，我会得到

员工[ID=null,name=null,age=null,location=null]

    import java.io.IOException;
    import com.fasterxml.jackson.core.JsonGenerationException;
    import com.fasterxml.jackson.databind.JsonMappingException;
    import com.fasterxml.jackson.databind.ObjectMapper;

public class JSONtoJavaPOJO {
public static void main(String[] args) {
    String json = "{\"id\":1,\"name\":\"Lokesh Gupta\",\"age\":34,\"location\":\"India\"}";

    ObjectMapper mapper = new ObjectMapper();
    try
    {
        Employee emp = mapper.readValue(json, Employee.class);

        System.out.println(emp);
    }
    catch (JsonGenerationException e)
    {
        e.printStackTrace();
    } catch (JsonMappingException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;



//@JsonIgnoreProperties(ignoreUnknown = true)
public class Employee
{
    private Integer id;
    private String name;
    private Integer age;
    private String location;



    public Employee() {
    }


    public Employee(Integer id, String name, Integer age, String location) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.location = location;
    }



    @Override
    public String toString() {
        return "Employee [id=" + id + ", name=" + name + ", age=" + age
                + ", location=" + location + "]";
    }
}

Answer 1

将setter和getter添加到Employee类中。