1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.configuration2.web;
18
19 import java.util.Collection;
20
21 import org.apache.commons.configuration2.AbstractConfiguration;
22
23 /**
24 * <p>
25 * An abstract base class for all web configurations.
26 * </p>
27 * <p>
28 * This class implements common functionality used by all web based configurations. E.g. some methods are not supported
29 * by configurations of this type, so they throw a {@code UnsupportedOperationException} exception.
30 * </p>
31 *
32 * @since 1.2
33 */
34 abstract class BaseWebConfiguration extends AbstractConfiguration {
35 /**
36 * Adds a property to this configuration. <strong>This operation is not supported and will throw an
37 * UnsupportedOperationException.</strong>
38 *
39 * @param key the key of the property
40 * @param obj the value to be added
41 * @throws UnsupportedOperationException because this operation is not allowed
42 */
43 @Override
44 protected void addPropertyDirect(final String key, final Object obj) {
45 throw new UnsupportedOperationException("Read only configuration");
46 }
47
48 /**
49 * Removes the property with the given key. <strong>This operation is not supported and will throw an
50 * UnsupportedOperationException.</strong>
51 *
52 * @param key the key of the property to be removed
53 * @throws UnsupportedOperationException because this operation is not allowed
54 */
55 @Override
56 protected void clearPropertyDirect(final String key) {
57 throw new UnsupportedOperationException("Read only configuration");
58 }
59
60 /**
61 * Checks whether the specified key is stored in this configuration.
62 *
63 * @param key the key
64 * @return a flag whether this key exists in this configuration
65 */
66 @Override
67 protected boolean containsKeyInternal(final String key) {
68 return getPropertyInternal(key) != null;
69 }
70
71 /**
72 * Tests whether this configuration contains one or more matches to this value. This operation stops at first match
73 * but may be more expensive than the containsKey method
74 * @since 2.11.0
75 */
76 @Override
77 protected boolean containsValueInternal(final Object value) {
78 return contains(getKeys(), value);
79 }
80
81 /**
82 * Takes care of list delimiters in property values. This method checks if delimiter parsing is enabled and the passed
83 * in value contains a delimiter character. If this is the case, a split operation is performed.
84 *
85 * @param value the property value to be examined
86 * @return the processed value
87 */
88 protected Object handleDelimiters(Object value) {
89 if (value instanceof String) {
90 final Collection<String> values = getListDelimiterHandler().split((String) value, true);
91 value = values.size() > 1 ? values : values.iterator().next();
92 }
93
94 return value;
95 }
96
97 /**
98 * Checks if this configuration is empty. This implementation makes use of the {@code getKeys()} method (which must be
99 * defined by concrete sub classes) to find out whether properties exist.
100 *
101 * @return a flag whether this configuration is empty
102 */
103 @Override
104 protected boolean isEmptyInternal() {
105 return !getKeysInternal().hasNext();
106 }
107 }