Json 转换地图<；字符串，字符串>；为嵌套属性键创建POJO

我需要将地图转换为POJO。我参考了下面的链接，对于简单的键（employeeId，firstName，lastName），它可以正常工作

对于关联（有线）密钥（department.departmentId、department.departmentName），它不起作用

import com.fasterxml.jackson.databind.DeserializationFeature；
导入com.fasterxml.jackson.databind.ObjectMapper；
公营雇员{
私人国际雇员ID；
私有字符串名；
私有字符串lastName；
私人部门,；
公共静态void main（字符串[]args）{
映射输入=constructMap（）；
最终ObjectMapper映射器=新ObjectMapper（）；
//禁用（反序列化功能。在未知属性上失败）；
final Employee=mapper.convertValue（输入，Employee.class）；
系统输出打印项次（员工）；
}
私有静态映射constructMap（）{
Map obj=新的HashMap（）；
对象put（“雇员ID”、“1”）；
obj.put（“名字”、“名字”）；
对象put（“姓氏”、“姓氏”）；
//obj.put（“部门ID”、“123”）；
//obj.put（“部门名称”、“物理”）；
返回obj；
}
}//员工类结束
公共课系{
私人int部门ID；
私有字符串departmentName；
}

映射的键和值是字符串，这是我从其他函数得到的。将有多个嵌套属性键，如department.departmentId或

---

address.addressId

您不需要使用

部门.departmentId

和

部门.departmentName

。而不是这样做，您必须在

部门.class

上调用第二个

convertValue

。之后，您可以将创建的

部门

设置为您的

员工

主要

系

public class Department
{
    private int departmentId;
    private String departmentName;

    public int getDepartmentId()
    {
        return departmentId;
    }

    public void setDepartmentId(int departmentId)
    {
        this.departmentId = departmentId;
    }

    public String getDepartmentName()
    {
        return departmentName;
    }

    public void setDepartmentName(String departmentName)
    {
        this.departmentName = departmentName;
    }
}

---

运行时，在线程“main”java.lang.IllegalArgumentException:无法识别的字段“department.departmentId”中获取此错误异常

public static void main(String[] args)
{
    Map<String,Object> input = constructMap();
    ObjectMapper mapper = new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    Employee employee = mapper.convertValue(input, Employee.class);
    Department department = mapper.convertValue(input, Department.class);
    employee.setDepartment(department);
    System.out.println(employee);
}

    private static Map<String, Object> constructMap()
    {
        Map<String, Object> obj = new HashMap<>();
        obj.put("employeeId", "1");
        obj.put("firstName", "firstName");
        obj.put("lastName", "lastName");
        obj.put("departmentId", "123");
        obj.put("departmentName", "Physics");

        return obj;
    }

public class Employee
{
    private int employeeId;
    private String firstName;
    private String lastName;
    private Department department;

    public int getEmployeeId()
    {
        return employeeId;
    }

    public void setEmployeeId(int employeeId)
    {
        this.employeeId = employeeId;
    }

    public String getFirstName()
    {
        return firstName;
    }

    public void setFirstName(String firstName)
    {
        this.firstName = firstName;
    }

    public String getLastName()
    {
        return lastName;
    }

    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }

    public Department getDepartment()
    {
        return department;
    }

    public void setDepartment(Department department)
    {
        this.department = department;
    }
}

public class Department
{
    private int departmentId;
    private String departmentName;

    public int getDepartmentId()
    {
        return departmentId;
    }

    public void setDepartmentId(int departmentId)
    {
        this.departmentId = departmentId;
    }

    public String getDepartmentName()
    {
        return departmentName;
    }

    public void setDepartmentName(String departmentName)
    {
        this.departmentName = departmentName;
    }
}