java json转义引号

String jsonMapStr = "{"system":"1,\"2\",3","createDate":"2017-02-21"}";
JSONObject jsonMap = JSONObject.fromObject(jsonMapStr);
Iterator<String> it = jsomMap.keys();
while(it.hasNext()){
String key = (String) it.next();
String value = (String) jsonMap.get(key);
System.out.println(key+":"+value);
}