大家平时用java对象转json字符串。null或者空字符串属性是不需要生成到json字符串里面的。
如下方式生成，没有使用的属性也会生成json字符串属性。
JSONArray jsonarray = JSONArray.fromObject(ecmMessageMap.values());msgObj = jsonarray.toString();
{"actionType":"","clientIp":"","ecServiceNumber":"","ecmMessageEventFlow":null,"endTime":"","eventId":"","faultEventFlowList":[],"groupId":"","psize":0,"receiver":"","receiverEcServiceNumber":"","sender":"","startTime":"","successEventIds":[]}
Gson使用：
Gson g = new Gson();msgObj = g.toJson(ecmMessage);
{"actionType":"1","successEventIds":[],"faultEventFlowList":[]}
如果大数据传输，或者存储到数据库，合理生成json字符串，会节约很大一部分存储空间和传输速度。比如交换监控mq数据json格式，交换监控容灾数据库存储。