使用fastJSON解析HashMap中的数据

男娘i 2022-08-09 06:54 215阅读 0赞

import java.util.HashMap;
     import java.util.Iterator;
     import java.util.Map;
     import java.util.Map.Entry;
     import java.util.Set;
    
     import com.alibaba.fastjson.JSON;
     import com.alibaba.fastjson.TypeReference;
    
    
    public class Demo {
        public static void main(String[] args) {
            Map<String, Student> map = new HashMap<String, Student>();
            Student stu1 = new Student("1", "莎拉波娃");
            Student stu2 = new Student("2", "布沙尔");
            Student stu3 = new Student("3", "哈勒普");
    
    
            map.put("00011", stu1);
            map.put("00012", stu2);
            map.put("00013", stu3);
    
    
            objectToStr(map);
            String str = "{'00011':{'id':'1','name':'silei'},'00012':{'id':'2','name':'布沙尔'},'00013':{'id':'3','name':'哈勒普'}}";
            strToObject(str);
        }
    
    
        public static void strToObject(String str) {
            Map<String, Student> map = (Map<String, Student>) JSON.parseObject(str, new TypeReference<Map<String, Student>>() {
            });
            Set<Entry<String, Student>> m = map.entrySet();
            Iterator<Entry<String, Student>> it = m.iterator();
            while (it.hasNext()) {
                Entry<String, Student> en = it.next();
                String id = en.getKey();
                Student stu = en.getValue();
                System.out.println(stu.getId() + "===" + stu.getName());
            }
            System.out.println(map.size());
        }
    
        // 把对象转换成JSON字符串
        public static void objectToStr(Map map) {
            String str = JSON.toJSONString(map);
            System.out.println(str);
        }
    }