[开发|java] java 将json转化java对象

1. 使用Jackson库将JSON转换为Java对象：
   安装依赖

<!-- Jackson Core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.12.5</version>
</dependency>

<!-- Jackson Databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.5</version>
</dependency>

代码示例：

import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonToObjectUsingJackson {
    
    
    public static void main(String[] args) {
    
    
        String jsonString = "{\"name\": \"John\", \"age\": 30, \"email\": \"[email protected]\"}";

        try {
    
    
            ObjectMapper objectMapper = new ObjectMapper();
            Person person = objectMapper.readValue(jsonString, Person.class);

            System.out.println("Name: " + person.getName());
            System.out.println("Age: " + person.getAge());
            System.out.println("Email: " + person.getEmail());
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }

    // Java类，用于映射JSON数据
    public static class Person {
    
    
        private String name;
        private int age;
        private String email;

        // 省略构造函数、getter和setter方法
        // 注意：字段名和JSON中的键名必须匹配，或者使用注解@JsonProperty指定映射关系
    }
}

2. 使用Gson库将JSON转换为Java对象：
   安装依赖

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.9</version>
</dependency>

代码示例：

import com.google.gson.Gson;

public class JsonToObjectUsingGson {
    
    
    public static void main(String[] args) {
    
    
        String jsonString = "{\"name\": \"John\", \"age\": 30, \"email\": \"[email protected]\"}";

        try {
    
    
            Gson gson = new Gson();
            Person person = gson.fromJson(jsonString, Person.class);

            System.out.println("Name: " + person.getName());
            System.out.println("Age: " + person.getAge());
            System.out.println("Email: " + person.getEmail());
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }

    // Java类，用于映射JSON数据
    public static class Person {
    
    
        private String name;
        private int age;
        private String email;

        // 省略构造函数、getter和setter方法
        // 注意：字段名和JSON中的键名必须匹配
    }
}