Java解析json数组三种情况

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());
    }
}

给大家推荐一个很好的自学网站,https://how2j.cn?p=77721，how2j,从基础到项目，一应俱全。可以先注册再学习，这样就可以记录学习进度咯！！！