我知道这个线程很老了，但是我遇到了这个问题，我想出了一个很酷的解决方案，它对许多人来说非常有用，因为它在许多方面纠正/扩展了 Volley 库。
我发现了一些不支持的开箱即用 Volley 功能：
- 这
JSONObjectRequest并不完美：您必须JSON在结尾处期待 a（参见 参考资料Response.Listener<JSONObject>）。
- Empty Responses（只有 200 状态）呢？
- 如果我直接想要我的 POJO，我该
ResponseListener怎么办？
我或多或少地在一个大的泛型类中编译了很多解决方案，以便为我引用的所有问题找到解决方案。
/**
* Created by laurentmeyer on 25/07/15.
*/
public class GenericRequest<T> extends JsonRequest<T> {
private final Gson gson = new Gson();
private final Class<T> clazz;
private final Map<String, String> headers;
// Used for request which do not return anything from the server
private boolean muteRequest = false;
/**
* Basically, this is the constructor which is called by the others.
* It allows you to send an object of type A to the server and expect a JSON representing a object of type B.
* The problem with the #JsonObjectRequest is that you expect a JSON at the end.
* We can do better than that, we can directly receive our POJO.
* That's what this class does.
*
* @param method: HTTP Method
* @param classtype: Classtype to parse the JSON coming from the server
* @param url: url to be called
* @param requestBody: The body being sent
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
private GenericRequest(int method, Class<T> classtype, String url, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
super(method, url, requestBody, listener,
errorListener);
clazz = classtype;
this.headers = headers;
configureRequest();
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, headers);
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, new HashMap<String, String>());
}
/**
* Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param requestBody: String to be sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, classtype, url, requestBody, listener,
errorListener, new HashMap<String, String>());
}
/**
* Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (Without header)
*
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(Request.Method.GET, url, classtype, "", listener, errorListener);
}
/**
* Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (With headers)
*
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
this(Request.Method.GET, classtype, url, "", listener, errorListener, headers);
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers, boolean mute) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, headers);
this.muteRequest = mute;
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (without header and muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, new HashMap<String, String>());
this.muteRequest = mute;
}
/**
* Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param requestBody: String to be sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
this(method, classtype, url, requestBody, listener,
errorListener, new HashMap<String, String>());
this.muteRequest = mute;
}
@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
// The magic of the mute request happens here
if (muteRequest) {
if (response.statusCode >= 200 && response.statusCode <= 299) {
// If the status is correct, we return a success but with a null object, because the server didn't return anything
return Response.success(null, HttpHeaderParser.parseCacheHeaders(response));
}
} else {
try {
// If it's not muted; we just need to create our POJO from the returned JSON and handle correctly the errors
String json = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
T parsedObject = gson.fromJson(json, clazz);
return Response.success(parsedObject, HttpHeaderParser.parseCacheHeaders(response));
} catch (UnsupportedEncodingException e) {
return Response.error(new ParseError(e));
} catch (JsonSyntaxException e) {
return Response.error(new ParseError(e));
}
}
return null;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return headers != null ? headers : super.getHeaders();
}
private void configureRequest() {
// Set retry policy
// Add headers, for auth for example
// ...
}
}
这似乎有点矫枉过正，但拥有所有这些构造函数非常酷，因为您拥有所有案例：
（主构造函数并不打算直接使用，尽管它当然是可能的）。
- 将响应解析为 POJO / Headers 手动设置 / POJO 发送的请求
- 将响应解析为 POJO / POJO 的请求以发送
- 请求响应解析为 POJO/要发送的字符串
- 响应解析为 POJO (GET) 的请求
- 请求的响应解析为 POJO (GET) / Headers 手动设置
- 请求无响应（200 - 空正文）/手动设置标头/POJO 发送
- 请求无响应（200 - 空体）/ POJO 发送
- 没有响应的请求（200 - 空正文）/要发送的字符串
当然，为了让它工作，你必须有谷歌的 GSON Lib；只需添加：
compile 'com.google.code.gson:gson:x.y.z'
到您的依赖项（当前版本是2.3.1）。