Jackson JSON Processor

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Jackson提供介面，可以再json和bean之間互相轉換

 

1. 一個例子

public class JsonToJavaBean {    public static void main(String[] args) {        String str="{\"student\":[{\"name\":\"leilei\",\"age\":23},{\"name\":\"leilei02\",\"age\":23}]}";        Student stu = null;        List<Student> list = null;        try {            ObjectMapper objectMapper=new ObjectMapper();            StudentList studentList=objectMapper.readValue(str, StudentList.class);                         list=studentList.getStudent();        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }         for(Student s:list){            System.out.println(s.getName()+"   "+s.getAge());        }    }}

 

2. 第二個例子

public static void main(String[] args) {        ArrayList<Student> list=new ArrayList<Student>();        Student s1=new Student();        s1.setName("leilei");        s1.setAge(23);        Student s2=new Student();        s2.setName("leilei02");        s2.setAge(23);        list.add(s1);        list.add(s2);                 StringWriter str=new StringWriter();                 ObjectMapper objectMapper=new ObjectMapper();        try {            objectMapper.writeValue(str, list);        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }           System.out.println(str);    }

 

我見到的用法

public Session fromJson(String json) throws JsonParseException, JsonMappingException, IOException {        return new ObjectMapper().readValue(json, Session.class);    }

 

總結

1. json在java裡是以string的形式存在的

2. 轉換需要的資訊是原始的json資料和轉換標準bean的定義

3. 可以轉換array和單個object