Java三方库-JSON库

记录下Jackson常用的功能

Jackson组成

jackson是java处理json的标准库

Jackson核心有三个包

core,annotation,databind, databind依赖前两者，所以使用时直接引入databind即可

		<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.17.0</version>
        </dependency>

JSON和对象系列

JSON和POJO互转示例

使用ObjectMapper进行JSON字符串和类，List，Map的互转，字段若私有，则需提供getter和setter方法

        ObjectMapper objectMapper = new ObjectMapper();
        Information information = new Information();
        information.setHost("12414142");
        information.setN ame("111");
        information.setPassword("123");
        Email email = new Email();
        email.setTitle("email-1");
        email.setInformation(information);

        String string = objectMapper.writeValueAsString(email);
        System.out.println(string);

        Email email1 = objectMapper.readValue(string, Email.class);
        System.out.println(email1);

List<Car> listCar = objectMapper.readValue(jsonCarArray, new TypeReference<List<Car>>(){
   });

Map<String, Object> map 
  = objectMapper.readValue(json, new TypeReference<Map<String,Object>>(){
   });

public class Email {
   
    private Information information;
    private String title;

    public Information getInformation() {
   
        return information;
    }

    public void setInformation(Information information) {
   
        this.information = information;
    }

    public String getTitle() {
   
        return title;
    }

    public void setTitle(String title) {
   
        this.title = title;
    }
}

public class Information {
   
    private String name;
    private String password;
    private String host;

    public String getName() {
   
        return name;
    }

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

    public String getPassword() {
   
        return password;
    }

    public void setPassword(String password) {
   
        this.password = password;
    }

    public String getHost() {
   
        return host;
    }

    public void setHost(String host) {
   
        this.host = host;
    }
}

// Note: can use getters/setters as well; here we just use public fields directly:
public class My