json和map互相转换

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

import java.util.Map;

public class JsonToMap {
    /**
     * fastjson的使用（处理json字符串、json数组）
     * 练习1：将json字符串转化成map，
     * 字符串：{"username":"qzcsbj", "password":"123456"}
     */
    public static void main(String[] args) {
        String str = "{\"username\":\"qzcsbj\", \"password\":\"123456\"}";
        //方法一
        Map maps = (Map) JSON.parse(str);
        System.out.println("使用JSON类来解析json字符串：");
        for (Object map:maps.entrySet()) {
            System.out.println(((Map.Entry)map).getKey() + " " + ((Map.Entry)map).getValue());
        }
        //方法二
        Map maps1 = JSON.parseObject(str);
        System.out.println("使用JSON类的parseObject解析json字符串：");
        for (Object key:maps1.keySet()) {
            System.out.println("key:" + key + ",value:" + maps1.get(key));
        }
        //方法三
        Map maps2 = JSON.parseObject(str,Map.class);
        System.out.println("使用JSON类，指定解析类，解析json字符串：");
        for (Object key:maps2.keySet()) {
            System.out.println("key:" + key + "->value:" + maps2.get(key));
        }
        //方法四
        Map maps3 = (Map)JSONObject.parse(str);
        System.out.println("使用JSONObject类的parse解析json字符串：");
        for (Object map:maps3.entrySet()) {
            System.out.println(((Map.Entry)map).getKey() + " " + ((Map.Entry)map).getValue());
        }
        //方法五
        Map maps4 = JSONObject.parseObject(str);
        System.out.println("使用JSONObject类的parseObject解析json字符串：");
        for (Object map:maps4.entrySet()) {
            System.out.println(((Map.Entry)map).getKey() + " " + ((Map.Entry)map).getValue());
        }
        //方法六
        Map maps5 = JSONObject.parseObject(str,Map.class);
        System.out.println("使用JSONObject类的parseObject,指定解析类，解析json字符串：");
        for (Object map:maps5.entrySet()) {
            System.out.println(((Map.Entry)map).getKey() + " " + ((Map.Entry)map).getValue());
        }


        //map转化成json
        JSON json = (JSON)JSONObject.toJSON(maps1);
        System.out.println(json);
        //map转化成json
        JSON json1 = (JSON)JSON.toJSON(maps1);
        System.out.println(json1);

    }
}

 <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.29</version>
</dependency>