目录

1. 三者之间的关系

2. ObjectMapper 主要方法

① Java与Json对象的相互转换

② Java与Json数组的相互转换

1. 三者之间的关系

• Jason 是存储和交换文本信息的一种语法
• Jackson 是当前最广泛用来序列化 和 反序列化  json 的 java 开源框架
• ObjectMapper 是 Jackson 中最常用的一个API

2. ObjectMapper 主要方法

• writeValueAsString ( )
• readValue ( )

① Java与Json对象的相互转换

public class Person {int id;String name;String password;public Person(int id, String name, String password) {this.id = id;this.name = name;this.password = password;}
}public class ObjectMapperTest {public static void main(String[] args) throws IOException {ObjectMapper objectMapper = new ObjectMapper();// Person对象转换为Json的格式Person person = new Person(1, "小明", "2222");String jsonString = objectMapper.writeValueAsString(person);System.out.println("JsonString: " + jsonString);// Json转换为Person对象Person person1 = objectMapper.readValue(jsonString, Person.class);System.out.println(person1.toString());}
}

② Java与Json数组的相互转换

public class ObjectMapperTest {public static void main(String[] args) throws IOException {ObjectMapper objectMapper = new ObjectMapper();//Java数组转换为JSON数组Person person1 = new Person(1, "张三", "33333");Person person2 = new Person(2, "李四", "44444");List personList = new ArrayList<>();personList.add(person1);personList.add(person2);String jsonString = objectMapper.writeValueAsString(personList);System.out.println("JsonString List: " + jsonString);}}