JSON字符串直接转换为目标对象，并测试是否是深度转换

• 提前说结果，可以深度转换对象和数组JSON字符串。

1 依赖

		<!-- 阿里JSON解析器 -->
        <dependency>
            <groupId>com.alibaba.fastjson2</groupId>
            <artifactId>fastjson2</artifactId>
            <version>2.0.25</version>
        </dependency>

2 实体类

• Person类

/**
 * @Author：胡云峰
 * @Date：2023/4/14 16:27
 */
public class Person {
    
    

    private String name;

    private int age;

    private String sex;

    private Date birthDate;

    private String avatar;

    private String car;

    private List<Pet> petList;

    public String getName() {
    
    
        return name;
    }

    public void setName(String name) {
    
    
        this.name = name;
    }

    public int getAge() {
    
    
        return age;
    }

    public void setAge(int age) {
    
    
        this.age = age;
    }

    public Date getBirthDate() {
    
    
        return birthDate;
    }

    public void setBirthDate(Date birthDate) {
    
    
        this.birthDate = birthDate;
    }

    public String getAvatar() {
    
    
        return avatar;
    }

    public void setAvatar(String avatar) {
    
    
        this.avatar = avatar;
    }

    public List<Pet> getPetList() {
    
    
        return petList;
    }

    public void setPetList(List<Pet> petList) {
    
    
        this.petList = petList;
    }

    public String getSex() {
    
    
        return sex;
    }

    public void setSex(String sex) {
    
    
        this.sex = sex;
    }

    public String getCar() {
    
    
        return car;
    }

    public void setCar(String car) {
    
    
        this.car = car;
    }

    @Override
    public String toString() {
    
    
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", sex='" + sex + '\'' +
                ", birthDate=" + birthDate +
                ", avatar='" + avatar + '\'' +
                ", car='" + car + '\'' +
                ", petList=" + petList +
                '}';
    }
}

• Car 类

/**
 * @Author：胡云峰
 * @Date：2023/4/20 15:36
 */
public class Car {
    
    

    private String carName;

    private String type;

    public String getCarName() {
    
    
        return carName;
    }

    public void setCarName(String carName) {
    
    
        this.carName = carName;
    }

    public String getType() {
    
    
        return type;
    }

    public void setType(String type) {
    
    
        this.type = type;
    }

    @Override
    public String toString() {
    
    
        return "Car{" +
                "carName='" + carName + '\'' +
                ", type='" + type + '\'' +
                '}';
    }
}

• Pet 类

/**
 * @Author：胡云峰
 * @Date：2023/4/14 16:33
 */
public class Pet {
    
    

    private String petName;

    private String category;

    public Pet() {
    
    
    }

    public Pet(String petName, String category) {
    
    
        this.petName = petName;
        this.category = category;
    }

    public String getPetName() {
    
    
        return petName;
    }

    public void setPetName(String petName) {
    
    
        this.petName = petName;
    }

    public String getCategory() {
    
    
        return category;
    }

    public void setCategory(String category) {
    
    
        this.category = category;
    }

    @Override
    public String toString() {
    
    
        return "Pet{" +
                "petName='" + petName + '\'' +
                ", category='" + category + '\'' +
                '}';
    }
}

3 测试用例

• 单个对象

{
    
    
    "name": "张三",
    "age": 16,
    "sex": "男"
}

• 数组对象

[
    {
    
    
    "name": "张三",
    "age": 16,
    "sex": "男"
    },
    {
    
    
    "name": "李四",
    "age": 18,
    "sex": "女"
    }
]

• 对象包含对象

{
    
    
    "name": "李四",
    "age": 18,
    "sex": "女",
    "car": {
    
    
        "carName": "桑塔纳",
        "type": "大众"
    }
}

• 对象包含数组

{
    
    
    "name": "李四",
    "age": 18,
    "sex": "女",
    "car": {
    
    
        "carName": "桑塔纳",
        "type": "大众"
    },
    "petList": [
        {
    
    
            "petName": "乐乐",
            "category": "狗"
        },
        {
    
    
            "petName": "欢欢",
            "category": "猫"
        }
    ]
}

4 测试

import com.alibaba.fastjson2.JSONArray;
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.JSONReader;
import com.yunfeng.generatepdfweb.domain.Person;

import java.util.List;

/**
 * @Author：胡云峰
 * @Date：2023/4/20 15:09
 */
public class TestFastJson2 {
    
    

    /**
     * 单个对象
     */
    private static final String jsonObjectStr = "{\"name\": \"张三\",\"age\": 16,\"sex\": \"男\"}";

    /**
     * 对象数组
     */
    private static final String jsonArrayStr = "[\n" +
            "{\"name\": \"张三\",\"age\": 16,\"sex\": \"男\"},\n" +
            "{\"name\": \"李四\",\"age\": 18,\"sex\": \"女\"}\n" +
            "]";

    /**
     * 测试深度转换对象
     */
    private static final String deepCopyObject = "{\n" +
            "    \"name\": \"张三\",\n" +
            "    \"age\": 16,\n" +
            "    \"sex\": \"男\",\n" +
            "    \"car\": {\n" +
            "        \"carName\": \"桑塔纳\",\n" +
            "        \"type\": \"大众\"\n" +
            "    }\n" +
            "}";

    /**
     * 测试深度转换数组对象
     */
    private static final String deepCopyList = "{\n" +
            "    \"name\": \"张三\",\n" +
            "    \"age\": 16,\n" +
            "    \"sex\": \"男\",\n" +
            "    \"car\": {\n" +
            "        \"carName\": \"桑塔纳\",\n" +
            "        \"type\": \"大众\"\n" +
            "    },\n" +
            "    \"petList\": [\n" +
            "                   {\n" +
            "                        \"petName\": \"乐乐\",\n" +
            "                        \"category\": \"狗\"\n" +
            "                   }, \n" +
            "                   {\n" +
            "                        \"petName\": \"欢欢\",\n" +
            "                        \"category\": \"猫\"\n" +
            "                   }\n" +
            "                ]\n" +
            "}";

    public static void main(String[] args) {
    
    
        // 1、单个对象的转换，自动忽略不匹配的
        // 方式一：字符串转换为JSONObject，JSONObject再转换为目标对象(Person)
        JSONObject jsonObject = JSONObject.parseObject(jsonObjectStr);
        Person person = jsonObject.toJavaObject(Person.class, JSONReader.Feature.IgnoreAutoTypeNotMatch);
        System.out.println("person = " + person);
        // 方式二：直接字符串转换为目标对象(Person)
        Person person1 = JSONObject.parseObject(jsonObjectStr, Person.class);
        System.out.println("person1 = " + person1);

        // 2、数组对象的转换，自动忽略不匹配的
        // 方式一：字符串转换为JSONArray,JSONArray再转换为目标list<Person>
        JSONArray jsonArray = JSONArray.parse(jsonArrayStr);
        List<Person> personList = jsonArray.toJavaList(Person.class, JSONReader.Feature.IgnoreAutoTypeNotMatch);
        System.out.println("personList = " + personList);
        // 方式二：直接字符串转化为目标list<Person>
        List<Person> personList1 = JSONArray.parseArray(jsonArrayStr, Person.class);
        System.out.println("personList1 = " + personList1);

        // 3、测试是否是深度转换
        Person deepPerson = JSONObject.parseObject(deepCopyObject, Person.class);
        // 结果显示对象可以深度转换对象
        System.out.println("deepPerson = " + deepPerson);

        // 4、测试List是否可以深度转换
        Person deepPerson2 = JSONObject.parseObject(deepCopyList, Person.class);
        // 结果显示对象可以深度转换List
        System.out.println("deepPerson2 = " + deepPerson2);
    }
}

5 结果

person = Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='null', petList=null}
person1 = Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='null', petList=null}
personList = [Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='null', petList=null}, Person{
    
    name='李四', age=18, sex='女', birthDate=null, avatar='null', car='null', petList=null}]
personList1 = [Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='null', petList=null}, Person{
    
    name='李四', age=18, sex='女', birthDate=null, avatar='null', car='null', petList=null}]
deepPerson = Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='{"carName":"桑塔纳","type":"大众"}', petList=null}
deepPerson2 = Person{
    
    name='张三', age=16, sex='男', birthDate=null, avatar='null', car='{"carName":"桑塔纳","type":"大众"}', petList=[Pet{
    
    petName='乐乐', category='狗'}, Pet{
    
    petName='欢欢', category='猫'}]}