我想使用android volley進行Gson請求。目前它工作正常,我很高興。但是,爲什麼我嘗試獲取列表<>或我的代碼集合不再有效。如何解析android volley gson請求到列表/對象集合
當前代碼:
public class ReviewModel
{
public long Id;
public Strring Description;
}
這裏是我如何用我的GSON類:
GsonRequest<ReviewModel> jsObjRequest = new GsonRequest<ReviewModel>(Request.Method.GET,
url, ReviewModel.class, new Response.Listener<ReviewModel>() {
@Override
public void onResponse(ReviewModel response) {
ReviewsHandleOkResponse(response);
}
}, new ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
ReviewsHandleErrorResponse(error);
}
});
Network.getInstance(getActivity()).addToRequestQueue(jsObjRequest);
}
這裏是我的排球GSON請求類:
public class GsonRequest<T> extends Request<T> {
private final Gson gson = new Gson();
private final Class<T> clazz;
private final Map<String, String> headers;
private final Map<String, String> params;
private final Listener<T> listener;
/**
* Make a GET request and return a parsed object from JSON.
*
* @param url
* URL of the request to make
* @param clazz
* Relevant class object, for Gson's reflection
* @param headers
* Map of request headers
*/
public GsonRequest(int method, String url, Class<T> clazz,
Map<String, String> headers, Map<String, String> params,
Listener<T> listener, ErrorListener errorListener) {
super(method, Network.getFullUrl(url), errorListener);
this.clazz = clazz;
this.headers = headers;
this.params = params;
this.listener = listener;
}
/**
* Recieves header
*
* @param method
* @param url
* @param clazz
* @param params
* @param listener
* @param errorListener
*/
public GsonRequest(int method, String url, Class<T> clazz,
Map<String, String> params, Listener<T> listener,
ErrorListener errorListener) {
super(method, Network.getFullUrl(url), errorListener);
this.clazz = clazz;
this.headers = new HashMap<String, String>();
this.params = params;
this.listener = listener;
}
/**
* No params or headers
*
* @param method
* @param url
* @param clazz
* @param listener
* @param errorListener
*/
public GsonRequest(int method, String url, Class<T> clazz,
Listener<T> listener, ErrorListener errorListener) {
super(method, Network.getFullUrl(url), errorListener);
this.clazz = clazz;
this.headers = new HashMap<String, String>();
this.params = new HashMap<String, String>();
this.listener = listener;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return headers != null ? headers : super.getHeaders();
}
@Override
public Map<String, String> getParams() throws AuthFailureError {
return params != null ? params : super.getParams();
}
@Override
protected void deliverResponse(T response) {
listener.onResponse(response);
}
@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
try {
String json = new String(response.data,
HttpHeaderParser.parseCharset(response.headers));
return Response.success(gson.fromJson(json, clazz),
HttpHeaderParser.parseCacheHeaders(response));
} catch (UnsupportedEncodingException e) {
return Response.error(new ParseError(e));
} catch (JsonSyntaxException e) {
return Response.error(new ParseError(e));
}
}
}
但是當我Rey和解析它到一個List<ReviewModel>
我得到編譯錯誤。
從我的研究,我需要做一些事情,如:
Type collectionType = new TypeToken<ArrayList<ReviewModel>>(){}.getType();
// api/v1/reviews/products/{productId}/{pageNumber}/{pageSize}
String url = "api/v1/reviews/products/" + productId + "/" + currentPage + "/" + pageSize;
GsonRequest<ArrayList<ReviewModel>> jsObjRequest = new GsonRequest<ArrayList<ReviewModel>>(Request.Method.GET,
url, (Class<ArrayList<ReviewModel>>) collectionType, new Response.Listener<ArrayList<ReviewModel>>() {
@Override
public void onResponse(ArrayList<ReviewModel> response) {
ReviewsHandleOkResponse(response);
}
}, new ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
ReviewsHandleErrorResponse(error);
}
});
Network.getInstance(getActivity()).addToRequestQueue(jsObjRequest);
}
,但是這給了我以下錯誤:
10-28 21:12:59.940: E/AndroidRuntime(28564): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.menu/com.menu.activities.ProductViewActivity}: java.lang.ClassCastException: com.google.gson.internal.$Gson$Types$ParameterizedTypeImpl cannot be cast to java.lang.Class
我是否需要修改我的GsonRequest類,和添加另一個不帶類型類的構造函數?
看看GSON的TypeToken後。 – njzk2 2014-10-28 19:16:37
我已經在我的文章中提到過,但是我無法弄清楚它是如何適合我的GsonRequest類的。 – Zapnologica 2014-10-28 19:27:28
'(Class>)collectionType'不轉換。 'Type'不是'Class'。修改你的'GsonRequest'來接受'Type'。 –
njzk2
2014-10-28 19:29:29