java - 如何知道 JSON 字符串是否可以无错误地转换为 JSONObject？

Question

如何处理这个问题，以免出现以下错误

JSONObject dataObject = new JSONObject(data);
String currentDynamicKey = "7";
JSONObject currentDynamicValue = dataObject.getJSONObject(currentDynamicKey);

错误:

org.json.JSONException: Value  at 7 of type java.lang.String cannot be converted to JSONObject

json数据:

{"2":{"id":2,"title":"Battleship game","enabled":"1","connection_alert":"1","prot":"2","port":"6410","analysis":"1","send_data":"Analysis Data box","regex":"\/HTTP\/1.1 404 Not Found\/","send_on":false,"analysis_alert_title":"404","analysis_alert_body":"not found","analysis_alert_body_false":"found"},"7":""}

如您所见，末尾的 7 为空。我该如何检查它是否为空？

Answer 1

只需使用optJSONObject(String name)代替getJSONObject(String name):

返回按名称映射的值(如果存在且为 JSONObject)。否则返回 null。

然后检查返回值。