fastJson学习笔记，对象序列化和反序列化

小灰灰 2021-05-07 20:35 739阅读 0赞

## 1.fastJson说明 ##

fastjson是阿里巴巴的开源JSON解析库，它可以解析JSON格式的字符串，  
支持将Java Bean序列化为JSON字符串，也可以从JSON字符串反序列化到JavaBean。

## 2.fastJson特点 ##

fastjson相对其他JSON库的特点是快，fastjson的API十分简洁。

## 3.springboot工程中使用，引入maven ##

<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.32</version>
    </dependency>

## 4.序列化一个对象成 JSON 字符串 ##

> 新建一个People实体

@Data
    public class People { 
    
        private String name;
    
        private Date birth;
    
        private int age;
    
        private String sex;
    
        private List<People> children;
    
    }

> 将People序列化

/**
         * 序列化一个对象成json字符串
         * @param args
         */
        public static void main(String[] args) { 
            People people = new People();
            people.setAge(30);
            people.setBirth(new Date());
            people.setName("大明");
            people.setSex("男");
            ArrayList<People> children = new ArrayList<>();
            for (int i=0 ; i<2 ; i++){ 
                People son = new People();
                son.setAge(6+i);
                son.setBirth(new Date());
                son.setName("小红");
                son.setSex("女");
                children.add(son);
            }
            people.setChildren(children);
            System.out.println(JSON.toJSONString(people));
        }

> 输出结果，我放到JsonHandle

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70]

## 5.反序列化一个 JSON 字符串成 Java 对象 ##

> 使用刚才输出的json字符串，反序列化成People对象

public static void main(String[] args) { 
            String json = "{\"age\":30,\"birth\":1589942848442," +
                    "\"children\":[{\"age\":6,\"birth\":1589942848442,\"name\":\"小红\",\"sex\":\"女\"}," +
                    "{\"age\":7,\"birth\":1589942848442,\"name\":\"小红\",\"sex\":\"女\"}]," +
                    "\"name\":\"大明\",\"sex\":\"男\"}";
            People people = JSON.parseObject(json, People.class);
            System.out.println(people.toString());
        }

> 输出结果

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70 1]

## 6.日期处理 ##

@Data
    public class People { 
    
        private String name;
    
        @JSONField(format = "yyyy-MM-dd hh:mm:ss")
        private Date birth;
    
        private int age;
    
        private String sex;
    
        private List<People> children;
    
    }

> 输出结果

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70 2]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70]: /images/20210505/7a098f2faa5e4dd188f5c7a29b510bd7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70 1]: /images/20210505/b364e2fea9964f3f8f64863cfb672955.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTAyNTM2Mg_size_16_color_FFFFFF_t_70 2]: /images/20210505/a2bcdbadf40e4de0bf173f139cd67fba.png