首先导入依赖
<dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.1.24</version></dependency>
要返回的数据为
{"code": 200,"msg": "success","newslist": [{"news": [{}],"desc": {},"riskarea": {"mid": ["上海市上海市黄浦区打浦桥街道顺昌路612弄20号", "上海市上海市嘉定区马陆镇康年路261号工地宿舍""],"high": ["北京市朝阳区南磨房（地区）乡南新园社区", "北京市朝阳区十八里店（地区）乡周家庄中路19号院", "北京市房山区窦店镇于庄村"]}}]
}
//要访问的网址String url=String.format("/ncov/index?key=d334721cf6eba2d619a5855420ec352c");StringBuffer json=new StringBuffer();try {URL u=new URL(url);URLConnection yc=u.openConnection();// 读取返回数据BufferedReader in=new BufferedReader(new InputStreamReader(yc.getInputStream(),"UTF-8"));String inputline = null;while((inputline=in.readLine())!=null){json.append(inputline);}in.close();} catch (MalformedURLException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}// 获得jsonObjectJSONObject jo=JSON.parseObject(json.toString());com.alibaba.fastjson.JSONArray newslist = jo.getJSONArray("newslist");List<String> list=new ArrayList<>();for(int i=0;i<newslist.size();i++) {JSONObject riskarea=newslist.getJSONObject(i).getJSONObject("riskarea");com.alibaba.fastjson.JSONArray mid=riskarea.getJSONArray("high");for(int j=0;j<mid.size();j++) {list.add(mid.getString(j));}}return list;
