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.functor.example.aggregator.nostore;
19
20 import org.apache.commons.functor.BinaryFunction;
21 import org.apache.commons.functor.aggregator.AbstractNoStoreAggregator;
22
23 /**
24 * Shows how to implement own aggregated function to use with
25 * {@link AbstractNoStoreAggregator}.
26 */
27 public class AggregatedFunctionSample {
28 /**
29 * Uses a custom function together with a nostore aggregator to provide a
30 * continuous logical OR in between all the values added to the aggregator.
31 */
32 public void useOwnFunction() throws Exception {
33 AbstractNoStoreAggregator<Boolean> or = new AbstractNoStoreAggregator<Boolean>( new OwnBinaryFunction() ) {
34 @Override
35 protected Boolean initialValue() {
36 return false;
37 }
38 };
39 or.add( false );
40 System.out.println( "OR : " + or.evaluate() );
41 or.add( true );
42 System.out.println( "OR : " + or.evaluate() );
43 or.add( false );
44 System.out.println( "OR : " + or.evaluate() );
45 }
46
47 /**
48 * This class implements a logical OR: it OR's the 2 parameters passed in
49 * and returns the result.
50 * (There are similar implementations already in functor, this is just to
51 * be used as an example for doing this with a nostore aggregator.
52 */
53 static class OwnBinaryFunction implements BinaryFunction<Boolean, Boolean, Boolean> {
54 public Boolean evaluate(Boolean left, Boolean right) {
55 return left.booleanValue() || right.booleanValue();
56 }
57 }
58 }