package com.example.demo.json;

 import java.util.Map;

 import com.alibaba.fastjson.JSON;

 import com.alibaba.fastjson.JSONArray;

 import com.alibaba.fastjson.JSONObject;

 import com.alibaba.fastjson.TypeReference;

 import com.example.demo.common.Person;

 public class JsonLib {

     //json字符串-简单对象型

     private static final String  JSON_OBJ_STR = "{\"studentName\":\"lily\",\"studentAge\":12}";

     //json字符串-数组类型

     private static final String  JSON_ARRAY_STR = "[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]";

     //复杂格式json字符串

     private static final String  COMPLEX_JSON_STR = "{\"teacherName\":\"crystall\",\"teacherAge\":27,\"course\":{\"courseName\":\"english\",\"code\":1270},\"students\":[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]}";

     @SuppressWarnings("unchecked")

    public static void main(String[] args) {

        //demoJson();

         //testJSONStrToJSONObject();//json字符串转化对象

         //testJSONStrToJSONArray();//json数组转化json对象

         testComplexJSONStrToJSONObject();//json对象嵌套json对象

    }

     /**

      * 复杂json格式字符串与JSONObject之间的转换

      */

     public static void testComplexJSONStrToJSONObject(){

         System.out.println(COMPLEX_JSON_STR);

         JSONObject jsonObject = JSON.parseObject(COMPLEX_JSON_STR);

         //JSONObject jsonObject1 = JSONObject.parseObject(COMPLEX_JSON_STR);//因为JSONObject继承了JSON，所以这样也是可以的

         System.out.println(jsonObject);

         String teacherName = jsonObject.getString("teacherName");

         Integer teacherAge = jsonObject.getInteger("teacherAge");

         JSONObject course = jsonObject.getJSONObject("course");

         JSONArray students = jsonObject.getJSONArray("students");

         System.out.println(teacherName+"------"+teacherAge+"===json对象===="+course+"----json数组----"+students);

         JSONArray jsonArray = JSON.parseArray(students.toString());

         System.out.println(jsonArray);

     }

     /**

      * json字符串-数组类型与JSONArray之间的转换

      */

     public static void testJSONStrToJSONArray(){

         JSONArray jsonArray = JSON.parseArray(JSON_ARRAY_STR);

         //JSONArray jsonArray1 = JSONArray.parseArray(JSON_ARRAY_STR);//因为JSONArray继承了JSON，所以这样也是可以的

         //遍历方式1

         int size = jsonArray.size();

         for (int i = 0; i < size; i++){

             JSONObject jsonObject = jsonArray.getJSONObject(i);

             System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));

         }

         //遍历方式2

         for (Object obj : jsonArray) {

             JSONObject jsonObject = (JSONObject) obj;

             System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));

         }

     }

     /**

      * json字符串-简单对象型与JSONObject之间的转换

      */

     public static void testJSONStrToJSONObject(){

         JSONObject jsonObject = JSON.parseObject(JSON_OBJ_STR);

         //JSONObject jsonObject1 = JSONObject.parseObject(JSON_OBJ_STR); //因为JSONObject继承了JSON，所以这样也是可以的

         System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));

     }

     public static void demoJson() {

         /**

             * 将 Json 形式的字符串转换为 Map

             */

            String str = "{\"name\":\"Tom\",\"age\":90}";

            JSONObject jsonObject = JSONObject.parseObject(str);

            Map<String, String> params = JSONObject.parseObject(jsonObject.toString(), new TypeReference<Map<String, String>>(){});

            System.out.println(params);

            /**

             * 将 Json 形式的字符串转换为 JavaBean

             */

              str = "{\"id\":\"A001\",\"name\":\"Jack\"}";

              jsonObject = JSONObject.parseObject(str);

              System.out.println(jsonObject);

              Person person = JSON.parseObject(str, new TypeReference<Person>() {});

              System.out.println(person.toString());

     }

 }