1 /*
2 * #%L
3 * Constant.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.builder.expression;
22
23 import com.allanbank.mongodb.bson.Element;
24
25 /**
26 * Represents constant value in an expression.
27 *
28 * @api.no This class is <b>NOT</b> part of the drivers API. This class may be
29 * mutated in incompatible ways between any two releases of the driver.
30 * @copyright 2012-2013, Allanbank Consulting, Inc., All Rights Reserved
31 */
32 public class Constant implements Expression {
33
34 /** The constant value. */
35 private final Element myConstant;
36
37 /**
38 * Creates a new Constant.
39 *
40 * @param constant
41 * The constant element.
42 */
43 public Constant(final Element constant) {
44 myConstant = constant;
45 }
46
47 /**
48 * {@inheritDoc}
49 * <p>
50 * Overridden to return the constant value's element with the specified
51 * name.
52 * </p>
53 */
54 @Override
55 public Element toElement(final String name) {
56 return myConstant.withName(name);
57 }
58
59 /**
60 * {@inheritDoc}
61 * <p>
62 * Overridden to return the constant value.
63 * </p>
64 * <blockquote>
65 *
66 * <pre>
67 * <code>
68 * value
69 * </code>
70 * </pre>
71 *
72 * </blockquote>
73 */
74 @Override
75 public String toString() {
76 return myConstant.getValueAsString();
77 }
78 }