1 /*
2 * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
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 package de.smartics.properties.spi.config.resolve;
17
18 import javax.annotation.concurrent.ThreadSafe;
19
20 import de.smartics.properties.api.config.domain.ConfigurationProperties;
21 import de.smartics.properties.api.config.domain.Property;
22 import de.smartics.properties.api.config.domain.UnknownPropertyException;
23 import de.smartics.properties.api.config.domain.key.ConfigurationKey;
24 import de.smartics.properties.api.core.domain.PropertyDescriptor;
25 import de.smartics.properties.api.core.domain.PropertyDescriptorRegistry;
26 import de.smartics.properties.api.core.domain.PropertyExpression;
27 import de.smartics.properties.api.core.domain.PropertyValidationException;
28
29 /**
30 * Simple interface on {@link ConfigurationProperties}.
31 *
32 * @impl the implementation is thread safe since it only provides read access to
33 * the wrapped configuration. If the configuration is accessed by other
34 * threads, it is not.
35 */
36 @ThreadSafe
37 public final class ConfigurationPropertiesResolveContext implements
38 ResolveContext
39 {
40 // ********************************* Fields *********************************
41
42 // --- constants ------------------------------------------------------------
43
44 /**
45 * The class version identifier.
46 */
47 private static final long serialVersionUID = 1L;
48
49 // --- members --------------------------------------------------------------
50
51 /**
52 * The registry to resolve property descriptors.
53 *
54 * @serial
55 */
56 private final PropertyDescriptorRegistry registry;
57
58 /**
59 * The configuration to adapt.
60 *
61 * @serial
62 */
63 private final ConfigurationProperties config;
64
65 // ****************************** Initializer *******************************
66
67 // ****************************** Constructors ******************************
68
69 /**
70 * Default constructor.
71 *
72 * @param registry the registry to resolve property descriptors.
73 * @param config the configuration to adapt.
74 */
75 public ConfigurationPropertiesResolveContext(
76 final PropertyDescriptorRegistry registry,
77 final ConfigurationProperties config)
78 {
79 this.registry = registry;
80 this.config = config;
81 }
82
83 // ****************************** Inner Classes *****************************
84
85 // ********************************* Methods ********************************
86
87 // --- init -----------------------------------------------------------------
88
89 // --- get&set --------------------------------------------------------------
90
91 /**
92 * {@inheritDoc}
93 *
94 * @see de.smartics.properties.spi.config.resolve.ResolveContext#getKey()
95 */
96 @Override
97 public ConfigurationKey<?> getKey()
98 {
99 return config.getKey();
100 }
101
102 // --- business -------------------------------------------------------------
103
104 /**
105 * {@inheritDoc}
106 *
107 * @see de.smartics.properties.spi.config.resolve.ResolveContext#get(java.lang.String)
108 */
109 @Override
110 public String get(final String key) throws IllegalArgumentException,
111 UnknownPropertyException, PropertyValidationException
112 {
113 final Property property = config.getProperty(key);
114 if (property == null)
115 {
116 throw new UnknownPropertyException(getKey(), key);
117 }
118 String value = property.getValue();
119
120 if (value == null)
121 {
122 final PropertyDescriptor descriptor = registry.get(key);
123 final PropertyExpression expression = descriptor.getDefaultExpression();
124 value = (expression != null ? expression.getExpression() : null);
125 }
126
127 return value;
128 }
129 // --- object basics --------------------------------------------------------
130
131 }