1 /*
2 * Copyright 2016 Andrew Rucker Jones.
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 com.opencsv.bean.customconverter;
17
18 import com.opencsv.bean.AbstractBeanField;
19 import com.opencsv.exceptions.CsvDataTypeMismatchException;
20 import org.apache.commons.lang3.StringUtils;
21
22 import java.util.ArrayList;
23 import java.util.Arrays;
24 import java.util.List;
25
26 /**
27 * This class takes a string and splits it on whitespace into a list of strings.
28 *
29 * @param <T> Type of the bean to be manipulated
30 * @param <I> Type of the index into a multivalued field
31 *
32 * @author Andrew Rucker Jones
33 */
34 public class ConvertSplitOnWhitespace<T, I> extends AbstractBeanField<T, I> {
35
36 /**
37 * Silence code style checker by adding a useless constructor.
38 */
39 public ConvertSplitOnWhitespace() {
40 }
41
42 /**
43 * Takes a string that is a list of substrings separated by whitespace and
44 * returns a list of the substrings.
45 * For example, the string "Jones Smith Cartwright Cooper" would be
46 * converted by this method to ("Jones", "Smith", "Cartwright", "Cooper").
47 * When might this be useful? A CSV has a set number of columns, but
48 * sometimes some fields might need to contain a variable number of entries.
49 * In this case, a list within one field of a CSV might make sense.
50 *
51 * @param value The string to be converted
52 * @return List<String> consisting of the substrings from the input
53 * that were separated in the input by whitespace
54 *
55 */
56 @Override
57 protected Object convert(String value) {
58 List<String> l = null;
59 if (!StringUtils.isEmpty(value)) {
60 l = new ArrayList<>(Arrays.asList(value.split("\\s+")));
61 }
62 return l;
63 }
64
65 /**
66 * This method takes the current value of the field in question in the bean
67 * passed in and converts it to a string.
68 *
69 * @return The concatenation of a list of strings, with every entry
70 * separated by a space
71 * @throws CsvDataTypeMismatchException If the field is not a list of strings
72 */
73 @Override
74 protected String convertToWrite(Object value) throws CsvDataTypeMismatchException {
75 String result = "";
76 try {
77 if(value != null) {
78 @SuppressWarnings("unchecked") List<String> values = (List<String>) value;
79 result = String.join(" ", values);
80 }
81 }
82 catch(ClassCastException e) {
83 CsvDataTypeMismatchException csve =
84 new CsvDataTypeMismatchException("The field must be of type List<String>.");
85 csve.initCause(e);
86 throw csve;
87 }
88 return result;
89 }
90
91 }