google的Gson使用

package com.cn.entity;

public class User {

    private String name;
    
    private Integer age;
    
    private String address;

    public User(){
        
    }
    
    public User(String name, Integer age, String address) {
        super();
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
    
}

package com.cn.util;

import com.google.gson.Gson;

public class JsonToObject {

    private static final Gson googleJson = new Gson();
    
    /**
     * 获取Gson常量，减少重复创建,在编译后就完成改变量初始化
     * @return
     */
    public static Gson getGoogleJson(){
        return googleJson;
    }
    
    /**
     * 直接获取
     * @param <T>
     * @param json
     * @param class1
     * @return
     */
    public static <T> Object jsonToObject(String json , Class<T> class1){
        return googleJson.fromJson(json, class1);
    }
    
}

package com.cn.util;

import com.google.gson.Gson;

public class ObjectToJsonUtil {
    
    private static final Gson googleJson = new Gson();
    
    /**
     * 获取Gson常量，减少重复创建,在编译后就完成改变量初始化
     * @return
     */
    public static Gson getGoogleJson(){
        return googleJson;
    }
    
    public static String objectToJson(Object object){
        return googleJson.toJson(object);
    }
    
}

package com.cn.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.cn.entity.User;
import com.cn.util.JsonToObject;
import com.cn.util.ObjectToJsonUtil;
import com.google.gson.reflect.TypeToken;

public class Test {

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
        //对象转json字符串
        User zhang = new User("zhang", 21, "深圳");        
        System.out.println("张某某转为json字符串："+ObjectToJsonUtil.objectToJson(zhang));
        
        //json转对象
        String json = "{‘name‘:‘wang‘,‘age‘:23,‘address‘:‘北京‘}";
        User wang = (User)JsonToObject.jsonToObject(json, User.class);
        System.out.println("json字符串转为王某某："+"名字-"+wang.getName()+",年龄-"+wang.getAge()+",地址-"+wang.getAddress());
        
        //字符串数组转json
        String[] strs = {"中国","湖北","武汉"};
        System.out.println(ObjectToJsonUtil.objectToJson(strs));
        
        //list对象转json
        List<User> list = new ArrayList<User>();
        list.add(new User("张三", 21, "北京"));
        list.add(new User("李四", 22, "上海"));
        list.add(new User("王五", 23, "深圳"));
        System.out.println(ObjectToJsonUtil.objectToJson(list));
        
        //map对象转json
        Map<String, User> map = new HashMap<String, User>();
        map.put("第一名", new User("张三", 21, "北京"));
        map.put("第二名", new User("李四", 22, "上海"));
        map.put("第三名", new User("王五", 23, "深圳"));
        System.out.println(ObjectToJsonUtil.objectToJson(map));
        
        //json转list集合
        String jsonList = "[{‘name‘:‘zhang‘,‘age‘:21,‘address‘:‘北京‘},{‘name‘:‘wang‘,‘age‘:22,‘address‘:‘上海‘},{‘name‘:‘zhao‘,‘age‘:23,‘address‘:‘深圳‘}]";
        List<User> personList = JsonToObject.getGoogleJson().fromJson(jsonList, new TypeToken<List<User>>(){}.getType());
        System.out.println(personList.get(0).getName()+"---"+personList.get(1).getName()+"---"+personList.get(2).getName());
        
        //json转map集合
        String jsonMap = "{‘one‘:{‘name‘:‘zhang‘,‘age‘:21,‘address‘:‘北京‘},‘two‘:{‘name‘:‘wang‘,‘age‘:22,‘address‘:‘上海‘},‘three‘:{‘name‘:‘zhao‘,‘age‘:23,‘address‘:‘深圳‘}}";
        Map<String, User> personMap = JsonToObject.getGoogleJson().fromJson(jsonMap, new TypeToken<Map<String , User>>(){}.getType());
        System.out.println("第一名："+personMap.get("one").getName()+"  第二名："+personMap.get("two").getName()+"  第三名："+personMap.get("three").getName());
    }
}