1 /*
2 * #%L
3 * ReplyIntegerCallback.java - mongodb-async-driver - Allanbank Consulting, Inc.
4 * %%
5 * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.
6 * %%
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20
21 package com.allanbank.mongodb.client.callback;
22
23 import java.util.List;
24
25 import com.allanbank.mongodb.Callback;
26 import com.allanbank.mongodb.MongoDbException;
27 import com.allanbank.mongodb.bson.Document;
28 import com.allanbank.mongodb.bson.Element;
29 import com.allanbank.mongodb.bson.NumericElement;
30 import com.allanbank.mongodb.client.message.Reply;
31 import com.allanbank.mongodb.error.ReplyException;
32
33 /**
34 * Callback to expect and extract a single document from the reply and then
35 * extract a contained {@link NumericElement} and coerce it to a integer value.
36 *
37 * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
38 * mutated in incompatible ways between any two releases of the driver.
39 * @copyright 2012-2013, Allanbank Consulting, Inc., All Rights Reserved
40 */
41 public class ReplyIntegerCallback extends AbstractReplyCallback<Integer> {
42
43 /** The default name for the long value to return. */
44 public static final String DEFAULT_NAME = "n";
45
46 /**
47 * The name of the {@link NumericElement value} expected in the reply
48 * document.
49 */
50 private final String myName;
51
52 /**
53 * Create a new ReplyIntegerCallback.
54 *
55 * @param results
56 * The callback to notify of the 'n' value.
57 */
58 public ReplyIntegerCallback(final Callback<Integer> results) {
59 this(DEFAULT_NAME, results);
60 }
61
62 /**
63 * Create a new ReplyIntegerCallback.
64 *
65 * @param name
66 * The name of the {@link NumericElement numeric} value.
67 * @param results
68 * The callback to notify of the 'n' value.
69 */
70 public ReplyIntegerCallback(final String name,
71 final Callback<Integer> results) {
72 super(results);
73
74 myName = name;
75 }
76
77 /**
78 * {@inheritDoc}
79 * <p>
80 * Creates an exception from the {@link Reply} if the 'n' field is missing.
81 * </p>
82 *
83 * @param reply
84 * The raw reply.
85 * @return The exception created.
86 */
87 @Override
88 protected MongoDbException asError(final Reply reply) {
89 MongoDbException error = super.asError(reply);
90 if (error == null) {
91 final List<Document> results = reply.getResults();
92 if (results.size() == 1) {
93 final Document doc = results.get(0);
94 final Element nElem = doc.get(myName);
95 if (toInt(nElem) < 0) {
96 error = new ReplyException(reply, "Missing '" + myName
97 + "' field in reply.");
98 }
99 }
100 }
101 return error;
102 }
103
104 /**
105 * {@inheritDoc}
106 * <p>
107 * Overridden to return the 'n' field in the reply document.
108 * </p>
109 *
110 * @see AbstractReplyCallback#convert(Reply)
111 */
112 @Override
113 protected Integer convert(final Reply reply) throws MongoDbException {
114 final List<Document> results = reply.getResults();
115 if (results.size() == 1) {
116 final Document doc = results.get(0);
117 final Element nElem = doc.get(myName);
118 return Integer.valueOf(toInt(nElem));
119 }
120
121 return Integer.valueOf(-1);
122 }
123 }