Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
EmptyDocument |
|
| 1.0;1 |
1 | /* | |
2 | * #%L | |
3 | * EmptyDocument.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 | package com.allanbank.mongodb.bson.impl; | |
21 | ||
22 | import java.util.Collections; | |
23 | import java.util.List; | |
24 | import java.util.Map; | |
25 | ||
26 | import com.allanbank.mongodb.bson.Element; | |
27 | ||
28 | /** | |
29 | * An immutable empty document. | |
30 | * | |
31 | * @api.yes This interface is part of the driver's API. Public and protected | |
32 | * members will be deprecated for at least 1 non-bugfix release | |
33 | * (version numbers are <major>.<minor>.<bugfix>) | |
34 | * before being removed or modified. | |
35 | * @copyright 2011, Allanbank Consulting, Inc., All Rights Reserved | |
36 | */ | |
37 | public class EmptyDocument extends AbstractDocument { | |
38 | ||
39 | /** An instance of the Empty Document. */ | |
40 | 1 | public static final EmptyDocument INSTANCE = new EmptyDocument(); |
41 | ||
42 | /** | |
43 | * The bytes to encode an empty document. Length (4) + terminal null (1) = | |
44 | * 5. | |
45 | */ | |
46 | public static final int SIZE = 5; | |
47 | ||
48 | /** Serialization version for the class. */ | |
49 | private static final long serialVersionUID = -2775918328146027036L; | |
50 | ||
51 | /** | |
52 | * Constructs a new {@link EmptyDocument}. | |
53 | */ | |
54 | public EmptyDocument() { | |
55 | 18 | super(); |
56 | 18 | } |
57 | ||
58 | /** | |
59 | * {@inheritDoc} | |
60 | * <p> | |
61 | * Overridden to return an empty list of elements. | |
62 | * </p> | |
63 | * | |
64 | * @return The elements in the document. | |
65 | */ | |
66 | @Override | |
67 | public List<Element> getElements() { | |
68 | 109 | return Collections.emptyList(); |
69 | } | |
70 | ||
71 | /** | |
72 | * Returns the size of the empty document when encoded as bytes. This is | |
73 | * always 5 bytes. | |
74 | * | |
75 | * @return The size of the document when encoded as bytes. | |
76 | */ | |
77 | @Override | |
78 | public long size() { | |
79 | 50 | return SIZE; // length (4) + terminal null (1). |
80 | } | |
81 | ||
82 | /** | |
83 | * {@inheritDoc} | |
84 | * <p> | |
85 | * Overridden to return an empty map as this document is always empty. | |
86 | * </p> | |
87 | */ | |
88 | @Override | |
89 | protected Map<String, Element> getElementMap() { | |
90 | 5 | return Collections.emptyMap(); |
91 | } | |
92 | } |