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。

在项目中引入pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>json</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>json</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.76</version>
        </dependency>
    </dependencies>
</project>

fastjson主要接口

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。

创建User类

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;
    }
}

创建group类

import com.alibaba.fastjson.annotation.JSONField;
import java.util.ArrayList;
import java.util.List;
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);
    }
}

json编码解码测试类

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
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);
//json编码
        String jsonString = JSON.toJSONString(group, SerializerFeature.UseSingleQuotes);
        System.out.println(jsonString);
//json解码
        Group groupDecode = JSON.parseObject(jsonString, Group.class);
        System.out.println(groupDecode.getName());
    }
}

SerializerFeature属性