View Javadoc
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.commons.lang3.builder;
19  
20  import org.apache.commons.lang3.function.FailableSupplier;
21  
22  /**
23   * Abstracts supplying an instance of {@code T}. Use to implement the builder pattern.
24   *
25   * @param <T> the type of instances to build.
26   * @param <B> the type of builder.
27   * @param <E> The kind of thrown exception or error.
28   * @since 3.14.0
29   */
30  public abstract class AbstractSupplier<T, B extends AbstractSupplier<T, B, E>, E extends Throwable> implements FailableSupplier<T, E> {
31  
32      /**
33       * Constructs a new instance.
34       */
35      public AbstractSupplier() {
36          // empty
37      }
38  
39      /**
40       * Returns this instance typed as the proper subclass type.
41       *
42       * @return this instance typed as the proper subclass type.
43       */
44      @SuppressWarnings("unchecked")
45      protected B asThis() {
46          return (B) this;
47      }
48  
49  }