将JavaBean对象转换为Map集合

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.13.0</version>
</dependency>

// 使用jackson将JavaBean对象属性转换为Map集合
public class JavaBeanToMapTest {
    public static void main(String[] args) {
        Subject subject = new Subject();
        subject.setId(10);
        subject.setName("Test");
        subject.setAddr("Beijing");
        Map<String, Object> map = new ObjectMapper().convertValue(subject, new TypeReference<Map<String, Object>>() {});
        // 输出：{id=10, name=Test, addr=Beijing}
        System.out.println(map);
        // 不转换null值
        subject.setAddr(null);
        map = new ObjectMapper().convertValue(subject, new TypeReference<Map<String, Object>>() {});
        // 输出：{id=10, name=Test}
        System.out.println(map);
    }

    static class Subject {
        Integer id;
        String name;
        // 如果希望null值不被转换，需要使用注解标注为Include.NON_NULL
        String addr;

        public Integer getId() {
            return id;
        }

        public void setId(Integer id) {
            this.id = id;
        }

        public String getName() {
            return name;
        }

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

        public String getAddr() {
            return addr;
        }

        public void setAddr(String addr) {
            this.addr = addr;
        }
    }
}