初步探索jackson对json格式处理

来源：互联网发布：网络电视要求的带宽编辑：程序博客网时间：2024/05/15 01:35

简介

Jackson可以轻松的将Java对象转换成json对象和xml文档，同样也可以将json、xml转换成Java对象。相比json-lib框架，Jackson所依赖的jar包较少，简单易用并且性能也要相对高些。而且Jackson社区相对比较活跃，更新速度也比较快。
jackson所需要的jar包可从此处下载

代码实战

javaimport com.fasterxml.jackson.annotation.JsonInclude.Include;import com.fasterxml.jackson.databind.JavaType;import com.fasterxml.jackson.databind.ObjectMapper;public class test {    public static void main(String[] args) {        ObjectMapper objectMapper = new ObjectMapper();        // 设置日期格式化        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));        // 设置null不序列化        objectMapper.setSerializationInclusion(Include.NON_NULL);        try {            //用户对象转为Json串            Person person1 = new Person("redgo", 20);            String json_person1 = objectMapper.writeValueAsString(person1);  //{"name":"redgo","age":20}            Person person2 = new Person("bluego", 22);            String json_person2 = objectMapper.writeValueAsString(person2);            //List对象转为Json串            List<Person> list = new ArrayList<Person>();            list.add(person1);            list.add(person2);            String json_list = objectMapper.writeValueAsString(list); //[{"name":"redgo","age":20},{"name":"bluego","age":22}]            //JSON串转为用户对象            person1 =objectMapper.readValue(json_person1, Person.class);            //JSON串转为List对象            JavaType javaType = objectMapper.getTypeFactory().constructParametricType(ArrayList.class, Person.class);            list = (List<Person>)objectMapper.readValue(json_list, javaType);          //用户组对象(包含List集合)转为Json串            PersonGroup personGroup = new PersonGroup("亲戚", list);            String json_personGroup = objectMapper.writeValueAsString(personGroup);                //{"name":"亲戚","persons":[{"age":20,"name":"redgo"},{"age":22,"name":"bluego"}]}            //JSON串转为用户组对象(包含List集合)            personGroup =objectMapper.readValue(json_personGroup, PersonGroup.class);        } catch (Exception e) {            e.printStackTrace();        }    }}

Person类

javapublic class Person {        private String name;        private int age;        public Person(){}        public Person(String name, int age){            this.name = name;            this.age = age;        }        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;        }        @Override        public String toString() {            return "Person [name=" + name + ", age=" + age + "]";        }}

PersonGroup类

javapublic class PersonGroup {        private String name;        private List<Person> persons = new ArrayList<Person>();        public PersonGroup(){};        public PersonGroup(String name, List<Person> persons){            this.name = name;            this.persons = persons;        };        public String getName() {            return name;        }        public void setName(String name) {            this.name = name;        }        public List<Person> getPersons() {            return persons;        }        public void setPersons(List<Person> persons) {            this.persons = persons;        }        @Override        public String toString() {            return "PersonGroup [name=" + name + ", persons=" + persons + "]";        } }

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