我有一个通用的Java Message对象，由以下json字符串表示：
{
"type": "Example",
"processTime": 3.4,
"payload":
{
"id": "someString",
"type": "anotherString",
"message": "yetAnotherString"
}
}
Java Message对象是通用的。我还有一个名为Event的对象。尝试使用gson将json转换为Message<Event>对象时，返回带有正确json值的Message对象，但嵌套通用对象以某种方式返回为“LinkedTreeMap”对象而不是{ {1}}对象。我知道这与类型擦除有关，但我似乎无法弄清楚如何从json返回Event。
这是我的Message<Event>：
main() public class App {
public static void main(String[] args) {
//The json string to convert into a "Message<Event>" object
String jsonString = "{\"type\":\"Example\",\"processTime\":3.4,\"payload\":{\"id\":\"someString\",\"type\":\"anotherString\",\"message\":\"yetAnotherString\"}}";
Message<Event> message = new Message<Event>();
message = message.convertJsonToObject(jsonString, Event.class);
System.out.println(message.getClass().getName()); //returns as a "Message" class -- as expected
System.out.println(message.getPayload().getClass().getName()); //returns as a "LinkedTreeMap" instead of an "Event" object
}
}
上课：
Message public class Message<T> {
private String type;
private double processTime;
private T payload;
public Message(String type, double processTime, T payload) {
this.type = type;
this.processTime = processTime;
this.payload = payload;
}
public Message() {
type = null;
processTime = 0;
payload = null;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public double getProcessTime() {
return processTime;
}
public void setProcessTime(double processTime) {
this.processTime = processTime;
}
public T getPayload() {
return payload;
}
public void setPayload(T payload) {
this.payload = payload;
}
public Message<T> convertJsonToObject(String jsonString, Class<T> classType) {
GsonBuilder gson = new GsonBuilder();
Type collectionType = new TypeToken<Message<T>>() {}.getType();
Message<T> myMessage = gson.create().fromJson(jsonString, collectionType);
return myMessage;
}
@Override
public String toString() {
return new Gson().toJson(this);
}
}
上课：
Event