1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.volley;
18 
19 /**
20  * Encapsulates a parsed response for delivery.
21  *
22  * @param <T> Parsed type of this response
23  */
24 public class Response<T> {
25 
26     /** Callback interface for delivering parsed responses. */
27     public interface Listener<T> {
28         /** Called when a response is received. */
onResponse(T response)29         public void onResponse(T response);
30     }
31 
32     /** Callback interface for delivering error responses. */
33     public interface ErrorListener {
34         /**
35          * Callback method that an error has been occurred with the
36          * provided error code and optional user-readable message.
37          */
onErrorResponse(VolleyError error)38         public void onErrorResponse(VolleyError error);
39     }
40 
41     /** Returns a successful response containing the parsed result. */
success(T result, Cache.Entry cacheEntry)42     public static <T> Response<T> success(T result, Cache.Entry cacheEntry) {
43         return new Response<T>(result, cacheEntry);
44     }
45 
46     /**
47      * Returns a failed response containing the given error code and an optional
48      * localized message displayed to the user.
49      */
error(VolleyError error)50     public static <T> Response<T> error(VolleyError error) {
51         return new Response<T>(error);
52     }
53 
54     /** Parsed response, or null in the case of error. */
55     public final T result;
56 
57     /** Cache metadata for this response, or null in the case of error. */
58     public final Cache.Entry cacheEntry;
59 
60     /** Detailed error information if <code>errorCode != OK</code>. */
61     public final VolleyError error;
62 
63     /** True if this response was a soft-expired one and a second one MAY be coming. */
64     public boolean intermediate = false;
65 
66     /**
67      * Returns whether this response is considered successful.
68      */
isSuccess()69     public boolean isSuccess() {
70         return error == null;
71     }
72 
73 
Response(T result, Cache.Entry cacheEntry)74     private Response(T result, Cache.Entry cacheEntry) {
75         this.result = result;
76         this.cacheEntry = cacheEntry;
77         this.error = null;
78     }
79 
Response(VolleyError error)80     private Response(VolleyError error) {
81         this.result = null;
82         this.cacheEntry = null;
83         this.error = error;
84     }
85 }
86