Question

我需要将文档存储到Elasticsearch索引中，因此我定义了一个映射。从我的Java客户端，我需要为其提供类似于Compony类的pojo。它具有很多重复的值。我可以使用对象合成模式来解决这个问题，但是Elasticsearch无法处理这种结构，因此它期望一种扁平的结构。

class Company {
    private String postalstreetName;
    private String postalHouseNumer;
    private String postalHouseLetter;
    private String postalHouseNumberAddition;
    private String postalZipCode;
    private String postalCity;
    private String postalCountry;

    private String visitorstreetName;
    private String visitorHouseNumer;
    private String visitorHouseLetter;
    private String visitorHouseNumberAddition;
    private String visitorZipCode;
    private String visitorCity;
    private String visitorCountry;

    private String establishmentstreetName;
    private String establishmentHouseNumer;
    private String establishmentHouseLetter;
    private String establishmentHouseNumberAddition;
    private String establishmentZipCode;
    private String establishmentCity;
    private String establishmentCountry;
}

我实际上希望像下面的pojo，并且以某种命名结构自动生成上面的pojo。

class Address {
    private String streetName;
    private String houseNumer;
    private String houseLetter;
    private String houseNumberAddition;
    private String zipCode;
    private String city;
    private String country;
}

class Company {
    private Address postalAddress;
    private Address visitorAddress;
    private Address establishmentAddress;
}

有人知道是否可以通过类似对象组成的pojo，自动为所有字段创建一个扁平化的pojo，这是否可行？

Answer 1

我为我的问题找到了解决方案。 Elasticsearch期望具有第一个示例中的结构的json对象。因此，我要做的是将@JsonUnwrapped添加到带有前缀值的字段中，所以我的Company类如下所示：

class Company {
    @JsonUnwrapped(prefix = "postal")
    private Address postalAddress;
    @JsonUnwrapped(prefix = "visitor")
    private Address visitorAddress;
    @JsonUnwrapped(prefix = "Establishment")
    private Address establishmentAddress;
}

结果将是：

{
  "postalStreetName":"",
  "postalHouseNumer":"",
  "postalHouseLetter":"",
  "postalHouseNumberAddition":"",
  "postalCity":"",
  "postalCountry":"",
  "visitorStreetName":"",
  "visitorHouseNumer":"",
  "visitorHouseLetter":"",
  "visitorHouseNumberAddition":"",
  "visitorCity":"",
  "visitorCountry":"",
  "establishmentStreetName":"",
  "establishmentHouseNumer":"",
  "establishmentHouseLetter":"",
  "establishmentHouseNumberAddition":"",
  "establishmentCity":"",
  "establishmentCountry":""
}

所以我不需要魔术般地创建那些pojo，因为杰克逊可以创建我需要的json文件。

有没有一种方法可以自动从具有对象组合的pojo生成平化的pojo

1 个答案: