java取json 的方法

public static void main(String[] args) {
String jsonStr = "[{\"varieties_type\":\"中证500指数\",\"open_granary\":\"0.0002\",\"close_granary\":\"0.0015\",\"days_close_granary\":\"0.00006\",\"delivery_granary\":\"0.0008\"}]";
// List li = (List) JsonHelper.getObjectByJSON(jsonStr);
// System.out.println(li.size());
//第一种取json方法
/*JSONArray jsonArr = JSONArray.fromObject(jsonStr);
System.out.println(jsonArr.size());
for (int i = 0; i < jsonArr.size(); i++) {
String jsonoStr = jsonArr.get(i).toString();
System.out.println(jsonStr);
Map<String, Object> json = (Map<String, Object>) JsonHelper.getObjectByJSON(jsonoStr);
System.out.println(json.size());
for(int j=0; j<json.size(); j++)
{
System.out.println(json.get());
}

}*/
//第一种取json方法
List<DataRow> li = (List<DataRow>) JsonHelper.getObjectByJSON(jsonStr);
InsertService Service = new InsertService();
DataRow dr=new DataRow();
System.out.println(li.size());
for (int i = 0; i < li.size(); i++) {
Map<String, Object> mappdata = li.get(i);
for (int j = 0; j < mappdata.size(); j++) {
//mappdata.get(liKey.get(j));
String varieties_type=(String) mappdata.get(liKey.get(0));
String open_granary=(String) mappdata.get(liKey.get(1));
String close_granary=(String) mappdata.get(liKey.get(2));
String days_close_granary=(String) mappdata.get(liKey.get(3));
String delivery_granary=(String) mappdata.get(liKey.get(4));
dr.set("varieties_type", varieties_type);
dr.set("open_granary", open_granary);
dr.set("close_granary", close_granary);
dr.set("days_close_granary", days_close_granary);
dr.set("delivery_granary", delivery_granary);
Service.insertinvestor(dr);
}
}
}