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.functor.example.kata.four;
18
19 import java.util.StringTokenizer;
20
21 import org.apache.commons.functor.UnaryFunction;
22
23 /**
24 * Evaluates the input String to extrace the nth whitespace
25 * delmited column.
26 *
27 * @version $Revision: 665786 $ $Date: 2008-06-09 19:17:39 +0200 (Mon, 09 Jun 2008) $
28 * @author Rodney Waldhoff
29 */
30 public final class NthColumn implements UnaryFunction<String, String> {
31 public NthColumn(int n) {
32 this.n = n;
33 }
34
35 public String evaluate(String obj) {
36 StringTokenizer toker = new StringTokenizer((String) obj);
37 for (int count = 0; count < n && toker.hasMoreTokens();count++) {
38 toker.nextToken();
39 }
40 return toker.hasMoreTokens() ? toker.nextToken() : null;
41 }
42
43 private final int n;
44
45 public static final NthColumn instance(int n) {
46 return new NthColumn(n);
47 }
48 }