fastjson

小灰灰 2022-06-04 02:07 201阅读 0赞

Fastjson是一个Java语言编写的高性能功能完善的JSON库。它采用一种“假定有序快速匹配”的算法，把JSON Parse的性能提升到极致，是目前Java语言中最快的JSON库。Fastjson接口简单易用，已经被广泛使用在缓存序列化、协议交互、Web输出、Android客户端等多种应用场景。

常见问题解答

[https://github.com/alibaba/fastjson/wiki/%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98][https_github.com_alibaba_fastjson_wiki_E5_B8_B8_E8_A7_81_E9_97_AE_E9_A2_98]

Maven:

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

## 使用介绍： ##

**Fastjson的最主要的使用入口是com.alibaba.fastjson.JSON**

import com.alibaba.fastjson.JSON;
    
    public static final Object parse(String text); // 把JSON文本parse为JSONObject或者JSONArray
    public static final JSONObject parseObject(String text)； // 把JSON文本parse成JSONObject
    public static final <T> T parseObject(String text, Class<T> clazz); // 把JSON文本parse为JavaBean
    public static final JSONArray parseArray(String text); // 把JSON文本parse成JSONArray
    public static final <T> List<T> parseArray(String text, Class<T> clazz); //把JSON文本parse成JavaBean集合
    public static final String toJSONString(Object object); // 将JavaBean序列化为JSON文本
    public static final String toJSONString(Object object, boolean prettyFormat); // 将JavaBean序列化为带格式的JSON文本
    public static final Object toJSON(Object javaObject); 将JavaBean转换为JSONObject或者JSONArray。

Google JSON 风格指南

你可以从这里了解如何更好的使用JSON：[https://github.com/darcyliu/google-styleguide/blob/master/JSONStyleGuide.md][https_github.com_darcyliu_google-styleguide_blob_master_JSONStyleGuide.md]

在 Spring 中集成 Fastjson

[https://github.com/alibaba/fastjson/wiki/%E5%9C%A8-Spring-%E4%B8%AD%E9%9B%86%E6%88%90-Fastjson][https_github.com_alibaba_fastjson_wiki_E5_9C_A8-Spring-_E4_B8_AD_E9_9B_86_E6_88_90-Fastjson]

## 简单例子 ##

public class Group { 
    
        @JSONField(serialize = false)
        private Long id;
        @JSONField(name = "groupName")
        private String name;
        private List<User> users = new ArrayList<User>();
    
        public Long getId() {
            return id;
        }
    
        public void setId(Long id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public List<User> getUsers() {
            return users;
        }
    
        public void setUsers(List<User> users) {
            this.users = users;
        }
    
        public void addUser(User user) {
            users.add(user);
        }
    }

public class User {
    
        private Long id;
        private String name;
    
        public Long getId() {
            return id;
        }
    
        public void setId(Long id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    }

public class Test {
        public static void main(String[] args) {
            Group group = new Group();
            group.setId(0L);
            group.setName("admin");
    
            User guestUser = new User();
            guestUser.setId(2L);
            guestUser.setName("guest");
    
            User rootUser = new User();
            rootUser.setId(3L);
            rootUser.setName("root");
    
            group.addUser(guestUser);
            group.addUser(rootUser);
    
            String jsonString = JSON.toJSONString(group, SerializerFeature.UseSingleQuotes);
    
            System.out.println(jsonString);
    
            Group groupDecode = JSON.parseObject(jsonString, Group.class);
            System.out.println(groupDecode.getName());
        }
    }

**输出：**

> \{‘groupName’:’admin’,’users’:\[\{‘id’:2,’name’:’guest’\},\{‘id’:3,’name’:’root’\}\]\}  
> admin

***SerializerFeature属性***

![这里写图片描述][SouthEast]

[https_github.com_alibaba_fastjson_wiki_E5_B8_B8_E8_A7_81_E9_97_AE_E9_A2_98]: https://github.com/alibaba/fastjson/wiki/%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98
[https_github.com_darcyliu_google-styleguide_blob_master_JSONStyleGuide.md]: https://github.com/darcyliu/google-styleguide/blob/master/JSONStyleGuide.md
[https_github.com_alibaba_fastjson_wiki_E5_9C_A8-Spring-_E4_B8_AD_E9_9B_86_E6_88_90-Fastjson]: https://github.com/alibaba/fastjson/wiki/%E5%9C%A8-Spring-%E4%B8%AD%E9%9B%86%E6%88%90-Fastjson
[SouthEast]: /images/20220604/111ebedac5374aca9a8f1ecf1a40e330.png