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
17package com.android.volley;
18
19/**
20 * Encapsulates a parsed response for delivery.
21 *
22 * @param <T> Parsed type of this response
23 */
24public class Response<T> {
25
26    /** Callback interface for delivering parsed responses. */
27    public interface Listener<T> {
28        /** Called when a response is received. */
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         */
38        public void onErrorResponse(VolleyError error);
39    }
40
41    /** Returns a successful response containing the parsed result. */
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     */
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     */
69    public boolean isSuccess() {
70        return error == null;
71    }
72
73
74    private Response(T result, Cache.Entry cacheEntry) {
75        this.result = result;
76        this.cacheEntry = cacheEntry;
77        this.error = null;
78    }
79
80    private Response(VolleyError error) {
81        this.result = null;
82        this.cacheEntry = null;
83        this.error = error;
84    }
85}
86