[json] The use of Jackson

All Jackson operations are performed through ObjectMapper object instances, which can be reused.

First define an instance:
ObjectMapper mapper = new ObjectMapper();

Define a Student class:

    package jackson;

    import java.util.Date;

    public class Student {

        private String name;
        private int age;
        private String position;
        private Date createTime;

        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 String getPosition() {
            return position;
        }

        public void setPosition(String position) {
            this.position = position;
        }

        public Date getCreateTime() {
            return createTime;
        }

        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }

        @Override
        public String toString() {
            return "Student [name=" + name + ", age=" + age + ", position="
                    + position + ", createTime=" + createTime + "]";
        }

    }

Prepare a string:
String jsonString = "{\"name\":\"king\",\"age\":21}";

General Operations: String to Object

     mapper.readValue(jsonString,Student.class);
     System.out.println(student);

Print out the result:

Student [name=king, age=21, position=null, createTime=null]