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.collections;
18
19 /**
20 * Defines a functor interface implemented by classes that do something.
21 * <p>
22 * A <code>Closure</code> represents a block of code which is executed from
23 * inside some block, function or iteration. It operates an input object.
24 * <p>
25 * Standard implementations of common closures are provided by
26 * {@link ClosureUtils}. These include method invocation and for/while loops.
27 *
28 * @param <T> the type that the closure acts on
29 * @since 1.0
30 * @version $Id: Closure.java 1361710 2012-07-15 15:00:21Z tn $
31 */
32 public interface Closure<T> {
33
34 /**
35 * Performs an action on the specified input object.
36 *
37 * @param input the input to execute on
38 * @throws ClassCastException (runtime) if the input is the wrong class
39 * @throws IllegalArgumentException (runtime) if the input is invalid
40 * @throws FunctorException (runtime) if any other error occurs
41 */
42 public void execute(T input);
43
44 }