我正在尝试向一个 ArrayList
添加一个值。
这是我编写的代码:
List<Map<String, Object>> list = new ArrayList<>();
list.put(1,"foo", (Object)"bar");
但是,这并不起作用。有人有什么想法吗?
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Map<String, Object> map = new HashMap<String, Object>();
map.put("foo", "bar");
list.add(map);
private List<Map<String, Object>> map_formula;
要保存到数据库,请传递此JSON:
{
"map_formula" : [
{
"A+" : "if(price<400),\"40000\",0",
"B" : "",
"c" : "",
"d" : "",
"e" : ""
},
{
"poor" : "value for poor",
"good" : "300",
"average" : "300",
"excellent" : "300"
}
]
}
for (Map<String, Object> stringObjectMap : obj.getMap_formula()) {
if (stringObjectMap.containsKey("key_name"){
System.err.println("calculation started");
}
}
list
中的元素必须是一个Map
。 - PM 77-1