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
18 package org.apache.logging.log4j.core.util;
19
20 /**
21 * A type of Plugin builder that can be used to configure and create a plugin instance using a Java DSL instead of
22 * through a configuration file. These builders are primarily useful for internal code and unit tests, but they can
23 * technically be used as a verbose alternative to configuration files.
24 *
25 * <p>
26 * When creating plugin builders, it is customary to create the builder class as a public static inner class
27 * called {@code Builder}. For instance, the builder class for
28 * {@link org.apache.logging.log4j.core.layout.PatternLayout PatternLayout} would be
29 * {@code PatternLayout.Builder}.
30 * </p>
31 *
32 * @param <T> the Plugin class this is a builder for.
33 */
34 public interface Builder<T> {
35
36 /**
37 * Builds the plugin object after all configuration has been set. This will use default values for any
38 * unspecified attributes for the plugin.
39 *
40 * @return the configured plugin instance.
41 * @throws org.apache.logging.log4j.core.config.ConfigurationException if there was an error building the plugin
42 * object.
43 */
44 T build();
45 }