fastjson：map转json字符串、json字符串转map、map根据key名拿value、JSONArray转list

1、map转json字符串：

List<SiteBean> list = new ArrayList();

list.add(siteBean);

list.add(siteBean);

Map<String,Object> map = new HashMap<>();

map.put("resultCode","0");

map.put("resultMsg","成功");

map.put("resultData",list);

map.put("count",list.size());

String jsonStr = new JSONObject(map).toString();

得到的jsonStr如下：

{"resultData":[{"abbr":"abbrOf11","begTime":"begTimeOf11","name":"nameOf11","objId":"objOf11","parZone":"parZoneOf11","zoneName":"zoneNameOf11"},{"abbr":"abbrOf12","begTime":"begTimeOf12","name":"nameOf12","objId":"objOf12","parZone":"parZoneOf12","zoneName":"zoneNameOf12"}],"resultCode":"0","count":2,"resultMsg":"成功"}

2、json字符串转map

Map<String, Object> map = (Map<String, Object>) JSONObject.parse(resultJsonStr);

map里面的resultData的value是一个JSONArray，JSONArry里面是JSONObject，一个JSONObject对应了一个SiteBean2

3、将map里面键为resultData的值拿出来，拿出的就是2里的JSONArray,再把JSONArray转成对应bean的list

List<SiteBean> siteList = new ArrayList<>();

siteList = (List<SiteBean>) map.get("resultData");

如果不成，可以用下面的方法：

JSONArray jsonArray = (JSONArray) resultMap.get("resultData");

List<SiteBean> list = JSONObject.parseArray(jsonArray.toString(),SiteBean.class);

4、活用，拿json字符串resultData里面只含有一个bean的转换成bean

JSONArray jsonArray = (JSONArray) resultDetailMap.get("resultData");

SiteDetailBean siteDetailBean= JSON.toJavaObject((JSONObject) jsonArray.get(0),SiteDetailBean.class);