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;
18
19 /**
20 * <p>
21 * Definition of an interface to be implemented by {@code Configuration} implementations which support a special
22 * initialization method.
23 * </p>
24 * <p>
25 * This interface is mainly evaluated by <em>configuration builder</em> implementations: If a newly created
26 * configuration instance implements this interface, the builder calls the {@code initialize()} method. This gives
27 * {@code Configuration} classes the opportunity to perform additional initializations after all properties passed to
28 * the builder have been set.
29 * </p>
30 * <p>
31 * Another use case for this interface is to perform initializations directly which otherwise would have been done
32 * lazily. Lazy initializations can be problematic regarding thread-safety. If in contrast a configuration instance has
33 * been fully initialized when it is returned from the builder, it may be used with a {@code NoOpSynchronizer} if it is
34 * not modified.
35 * </p>
36 *
37 * @since 2.0
38 */
39 public interface Initializable {
40 /**
41 * Initializes this object. A concrete implementation can use this method to perform arbitrary initialization.
42 * Typically, this method is invoked by a <em>configuration builder</em>. In this case, the builder's lock is held, so
43 * that all member fields set by this method are safely published.
44 */
45 void initialize();
46 }