@Data
public class Account {

    @JsonUnwrapped
    private Location location;
    @JsonUnwrapped
    private PersonInfo personInfo;

    @Data
    public static class Location {
        private String provinceName;
        private String countyName;
    }

    @Data
    public static class PersonInfo {
        private String userName;
        private String fullName;
    }

}

未扁平化之前：

{
    "location": {
        "provinceName":"广东",
        "countyName":"深圳"
    },
    "personInfo": {
        "userName": "111",
        "fullName": "222"
    }
}

使用 @JsonUnwrapped 扁平对象之后：

{
  "provinceName":"广东",
  "countyName":"深圳",
  "userName": "111",
  "fullName": "222"
}

不同对象间有相同名称的属性？会怎么样，会报错吗？答案是不会，都会正常返回，只是对前端而言有歧义罢了~，此时可以借助 @JsonUnwrapped 的 suffix 和 prefix 来规避这个问题

JsonUnwrapped