java - 我应该如何将请求主体映射到另一个对象，同时保持相同的子关系？

Question

我有一个带有此模型类的请求正文:

public class IvrRequest {
    int age;
    String name;
    String address;
    List<IvrRequest> children;
}

我想将其映射到另一个类模型，例如:

public class IvrMapper {
    int id;
    String name;
    List<IvrMapper> resourceElements;
}

我应该使用什么方法？

示例:-

{
    "age":16,
    "name":"Rohit",
    "address":"adgsgdsdfgsdfgsf",
    "children":[
    {
        "age":16,
        "name":"Rohit",
        "address":"adgsgdsdfgsdfgsf",
        "children":[{
            "age":16,
            "name":"Rohit",
            "address":"adgsgdsdfgsdfgsf"                
        }]
    },
    {
        "age":45,
        "name":"Singh",
        "address":"45afasdfas54df6asdf",
        "children":[{
            "age":55,
            "name":"nitin",
            "address":"@%^%@#^Ghagdhasdhg"              
        }]
    }]
}

这是请求正文的示例。

Answer 1

您没有指定您使用哪个库，所以我建议使用 Jackson它允许快速轻松地从 JSON 到 Java 模型以及从一个 POJO 到另一个 POJO 反序列化。如果您无法更改类或类属于 3-rd party 库，您可以随时使用 MixIn feature 。下面的示例展示了如何:

• 将 JSON 反序列化为 IvrRequest
• 将 JSON 反序列化为 IvrMapper
• 将 IvrRequest 转换为 IvrMapper

简单的应用程序:

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.util.List;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        File jsonFile = new File("./resource/test.json").getAbsoluteFile();

        ObjectMapper mapper = new ObjectMapper();
        mapper.addMixIn(IvrMapper.class, IvrMapperMixIn.class);

        System.out.println("Parse IvrRequest model: ");
        IvrRequest ivrRequest = mapper.readValue(jsonFile, IvrRequest.class);
        System.out.println(ivrRequest);

        System.out.println("Parse IvrMapper model: ");
        System.out.println(mapper.readValue(jsonFile, IvrMapper.class));

        System.out.println("Convert IvrRequest to IvrMapper");
        System.out.println(mapper.convertValue(ivrRequest, IvrMapper.class));
    }
}

@JsonIgnoreProperties(ignoreUnknown = true)
interface IvrMapperMixIn {

    @JsonProperty("age")
    int getId();

    @JsonProperty("children")
    List<IvrMapper> getResourceElements();
}

class IvrRequest {

    private int age;
    private String name;
    private String address;
    private List<IvrRequest> children;

    // getters, setters, toString
}

class IvrMapper {
    private int id;
    private String name;
    private List<IvrMapper> resourceElements;

    // getters, setters, toString
}

以上应用程序打印:

Parse IvrRequest model: 
age=16, name='Rohit', address='adgsgdsdfgsdfgsf'
 children=
    age=16, name='Rohit', address='adgsgdsdfgsdfgsf'
 children=
    age=16, name='Rohit', address='adgsgdsdfgsdfgsf'

    age=45, name='Singh', address='45afasdfas54df6asdf'
 children=
    age=55, name='nitin', address='@%^%@#^Ghagdhasdhg'


Parse IvrMapper model: 
id=16, name='Rohit'
 resourceElements=
    id=16, name='Rohit'
 resourceElements=
    id=16, name='Rohit'

    id=45, name='Singh'
 resourceElements=
    id=55, name='nitin'


Convert IvrRequest to IvrMapper
id=16, name='Rohit'
 resourceElements=
    id=16, name='Rohit'
 resourceElements=
    id=16, name='Rohit'

    id=45, name='Singh'
 resourceElements=
    id=55, name='nitin'