1 /*
2 * Copyright 2007 Kasper B. Graversen
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.supercsv.cellprocessor;
17
18 import org.supercsv.cellprocessor.ift.BoolCellProcessor;
19 import org.supercsv.cellprocessor.ift.CellProcessor;
20 import org.supercsv.cellprocessor.ift.DateCellProcessor;
21 import org.supercsv.cellprocessor.ift.DoubleCellProcessor;
22 import org.supercsv.cellprocessor.ift.LongCellProcessor;
23 import org.supercsv.cellprocessor.ift.StringCellProcessor;
24 import org.supercsv.exception.SuperCsvCellProcessorException;
25 import org.supercsv.util.CsvContext;
26
27 /**
28 * This processor is used in the situations you want to be able to check for the presence of a "special
29 * token". Such a token could be the string "[empty]" which could denote that a column is different from the empty
30 * string "".
31 * <p>
32 * For example, to convert the String <tt>"[empty]"</tt> to -1 (an int representing 'empty') you could use <code>
33 * new Token("[empty]", -1)
34 * </code>
35 * <p>
36 * Comparison between the input and the <tt>token</tt> is based on the object's <tt>equals()</tt> method.
37 *
38 * @since 1.02
39 * @author Kasper B. Graversen
40 */
41 public class Token extends CellProcessorAdaptor implements BoolCellProcessor, DateCellProcessor, DoubleCellProcessor,
42 LongCellProcessor, StringCellProcessor {
43
44 private final Object returnValue;
45 private final Object token;
46
47 /**
48 * Constructs a new <tt>Token</tt> processor, which returns the supplied value if the token is encountered,
49 * otherwise it returns the input unchanged.
50 *
51 * @param token
52 * the token
53 * @param returnValue
54 * the value to return if the token is encountered
55 */
56 public Token(final Object token, final Object returnValue) {
57 super();
58 this.token = token;
59 this.returnValue = returnValue;
60 }
61
62 /**
63 * Constructs a new <tt>Token</tt> processor, which returns the supplied value if the token is encountered,
64 * otherwise it passes the input unchanged to the next processor in the chain.
65 *
66 * @param token
67 * the token
68 * @param returnValue
69 * the value to return if the token is encountered
70 * @param next
71 * the next processor in the chain
72 * @throws NullPointerException
73 * if next is null
74 */
75 public Token(final Object token, final Object returnValue, final CellProcessor next) {
76 super(next);
77 this.token = token;
78 this.returnValue = returnValue;
79 }
80
81 /**
82 * {@inheritDoc}
83 *
84 * @throws SuperCsvCellProcessorException
85 * if value is null
86 */
87 public Object execute(final Object value, final CsvContext context) {
88 validateInputNotNull(value, context);
89
90 if( value.equals(token) ) {
91 return returnValue;
92 }
93
94 return next.execute(value, context);
95 }
96 }