GSON解析通用Json数组

一尘不染

GSON解析通用Json数组

json

但是我无法从中得到答案。上面链接的答案：

public static List<MapData> getData(){
    Gson gson = new Gson();
    String jsonString = "[{\"id\":18,\"city\":\"test\",\"street\":\"test 1\",\"zipcode\":121209,\"state\":\"IL\",\"lat\":32.158138,\"lng\":34.807838},{\"id\":19,\"city\":\"test\",\"street\":\"1\",\"zipcode\":76812,\"state\":\"IL\",\"lat\":32.161041,\"lng\":34.810410}]";
    Type type = new TypeToken<List<MapData>>(){}.getType();
    return gson.fromJson(jsonString, type);     
}

它运作良好，但我想对泛型使用隐式运算符。见下文：

public static <T> List<T> getData(Class<T> classT){
    Gson gson = new Gson();
    String jsonString = "[{\"id\":18,\"city\":\"test\",\"street\":\"test 1\",\"zipcode\":121209,\"state\":\"IL\",\"lat\":32.158138,\"lng\":34.807838},{\"id\":19,\"city\":\"test\",\"street\":\"1\",\"zipcode\":76812,\"state\":\"IL\",\"lat\":32.161041,\"lng\":34.810410}]";
    Type type = new TypeToken<List<T>>(){}.getType();
    return gson.fromJson(jsonString, type);
}

然后，我尝试将Class参数传递给方法：

List<MapData> data = getData(MapData.class);
System.out.println(data.get(0).city);

然后出现一个错误：

java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to com.ssc.ctq.nav.util.MapData

谁能告诉我为什么会出现此错误？TypeToken类不支持隐式运算符吗？

阅读 813

2020-07-27

共1个答案

一尘不染

您可以这样：

     Gson gson = new Gson();

    String jsonString = "[{\"id\":18,\"city\":\"test\",\"street\":\"test 1\",\"zipcode\":121209,\"state\":\"IL\",\"lat\":32.158138,\"lng\":34.807838},{\"id\":19,\"city\":\"test\",\"street\":\"1\",\"zipcode\":76812,\"state\":\"IL\",\"lat\":32.161041,\"lng\":34.810410}]";

    List<Map> tmpList = gson.fromJson(jsonString);
    List<T> resultList = new Arraylist<T>(tmplist.size());
    for(Map map:tmpList){
       String tmpJson = gson.toJson(map);
       resultList.add(gson.fromJson(tmpJson, classT));
    }
    return resultList;

2020-07-27