Java下利用Jackson进行Json的转化解析

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1.导入相应jackson的jar包

2.需要转化解析的类Person.java

public class Person{    private String name;    private int 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;    }}

3.Java对象转Json

public class JacksonTest {      public static void main(String[] args) throws IOException{        ObjectMapper  objectMapper = new ObjectMapper();        Person person1 = new Person();        person1.setName("sbw");        person1.setAge(24);        Person person2 = new Person();        person2.setName("gy");        person2.setAge(25);        /**         * 普通对象转Json         */        String json = objectMapper.writeValueAsString(person1);//转为字符串        System.out.println(json);        /**         * List转Json         */        List<Person> list = new ArrayList<Person>();        list.add(person1);        list.add(person2);        String listJson = objectMapper.writeValueAsString(list);        System.out.println(listJson);        /**         * Map转Json         */        Map<String, Person> map = new HashMap<String, Person>();            map.put("person1", person1);        map.put("person2", person2);        objectMapper.writeValue(System.out, map);//System.out已可以转为其他流    }}

执行结果：

这里写图片描述

4.Json转Java对象

public class JacksonTest {      public static void main(String[] args) throws IOException{        ObjectMapper  objectMapper = new ObjectMapper();            String json = "{\"name\":\"sbw\",\"age\":24}";//普通        String listJson = "[{\"name\":\"sbw\",\"age\":24},{\"name\":\"gy\",\"age\":25}]";//List        String mapJson = "{\"person1\":{\"name\":\"sbw\",\"age\":24},\"person2\":{\"name\":\"gy\",\"age\":25}}";//Map        /**         * Json转Java对象         */        Person person = objectMapper.readValue(json, Person.class);        System.out.println(person.getName() + " " + person.getAge());        System.out.println();        /**         * Json转List         */        @SuppressWarnings("unchecked")        List<LinkedHashMap<String, Object>> list = objectMapper.readValue(listJson, List.class);        for(LinkedHashMap<String, Object> ll : list){            for(Map.Entry<String, Object> mm: ll.entrySet()){                System.out.println(mm.getKey() + " " + mm.getValue());            }        }        System.out.println();        /**         *Json转数组         */        Person[] per = objectMapper.readValue(listJson, Person[].class);        for(Person p : per){            System.out.println(p.getName() + " " + p.getAge());        }        System.out.println();        /**         * Json转Map         */        @SuppressWarnings("unchecked")        Map<String, Person> map = objectMapper.readValue(mapJson, Map.class);        for(Map.Entry<String, Person> m : map.entrySet()){            System.out.println(m.getKey() + " " + m.getValue());                }    }}

执行结果：

这里写图片描述

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