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 java.text.DecimalFormat;
19
20 import org.supercsv.cellprocessor.ift.DoubleCellProcessor;
21 import org.supercsv.cellprocessor.ift.LongCellProcessor;
22 import org.supercsv.cellprocessor.ift.StringCellProcessor;
23 import org.supercsv.exception.SuperCsvCellProcessorException;
24 import org.supercsv.util.CsvContext;
25
26 /**
27 * Converts a double into a formatted string using the {@link DecimalFormat} class and the default locale. This is
28 * useful, when you need to show numbers with a specific number of digits.
29 * <p>
30 * Please be aware that the constructors that use <tt>DecimalFormat</tt> are not thread-safe, so it is generally better
31 * to use the constructors that accept a date format String.
32 * <p>
33 * In the format string, the following characters are defined as : <br>
34 *
35 * <pre>
36 * 0 - means Digit
37 * # - means Digit, zero shows as absent (works only as zero padding on the right hand side of the number)
38 * . - means Decimal separator or monetary decimal separator
39 * - - means Minus sign
40 * , - means Grouping separator
41 * </pre>
42 *
43 * <br>
44 * If you want to convert from a String to a decimal, use the {@link ParseDouble} or {@link ParseBigDecimal} processor.
45 *
46 * @since 1.50
47 * @author Kasper B. Graversen
48 * @author James Bassett
49 */
50 public class FmtNumber extends CellProcessorAdaptor implements DoubleCellProcessor, LongCellProcessor {
51
52 /** the decimal format string */
53 private final String decimalFormat;
54
55 /** the decimal format object - not thread safe */
56 private final DecimalFormat formatter;
57
58 /**
59 * Constructs a new <tt>FmtNumber</tt> processor, which converts a double into a formatted string using the supplied
60 * decimal format String. This constructor is thread-safe.
61 *
62 * @param decimalFormat
63 * the decimal format String (see {@link DecimalFormat})
64 * @throws NullPointerException
65 * if decimalFormat is null
66 */
67 public FmtNumber(final String decimalFormat) {
68 super();
69 checkPreconditions(decimalFormat);
70 this.decimalFormat = decimalFormat;
71 this.formatter = null;
72 }
73
74 /**
75 * Constructs a new <tt>FmtNumber</tt> processor, which converts a double into a formatted string using the supplied
76 * decimal format String, then calls the next processor in the chain. This constructor is thread-safe.
77 *
78 * @param decimalFormat
79 * the decimal format String (see {@link DecimalFormat})
80 * @param next
81 * the next processor in the chain
82 * @throws NullPointerException
83 * if decimalFormat or next is null
84 */
85 public FmtNumber(final String decimalFormat, final StringCellProcessor next) {
86 super(next);
87 checkPreconditions(decimalFormat);
88 this.decimalFormat = decimalFormat;
89 this.formatter = null;
90 }
91
92 /**
93 * Constructs a new <tt>FmtNumber</tt> processor, which converts a double into a formatted string using the supplied
94 * decimal format. This constructor is not thread-safe.
95 *
96 * @param formatter
97 * the DecimalFormat
98 * @throws NullPointerException
99 * if formatter is null
100 */
101 public FmtNumber(final DecimalFormat formatter) {
102 super();
103 checkPreconditions(formatter);
104 this.formatter = formatter;
105 this.decimalFormat = null;
106 }
107
108 /**
109 * Constructs a new <tt>FmtNumber</tt> processor, which converts a double into a formatted string using the supplied
110 * decimal format, then calls the next processor in the chain. This constructor is not thread-safe.
111 *
112 * @param formatter
113 * the DecimalFormat
114 * @param next
115 * the next processor in the chain
116 * @throws NullPointerException
117 * if formatter or next is null
118 */
119 public FmtNumber(final DecimalFormat formatter, final StringCellProcessor next) {
120 super(next);
121 checkPreconditions(formatter);
122 this.formatter = formatter;
123 this.decimalFormat = null;
124 }
125
126 /**
127 * Checks the preconditions for creating a new FmtNumber processor with a date format String.
128 *
129 * @param dateFormat
130 * the date format String
131 * @throws NullPointerException
132 * if dateFormat is null
133 */
134 private static void checkPreconditions(final String dateFormat) {
135 if( dateFormat == null ) {
136 throw new NullPointerException("dateFormat should not be null");
137 }
138 }
139
140 /**
141 * Checks the preconditions for creating a new FmtNumber processor with a DecimalFormat.
142 *
143 * @param formatter
144 * the DecimalFormat
145 * @throws NullPointerException
146 * if formatter is null
147 */
148 private static void checkPreconditions(final DecimalFormat formatter) {
149 if( formatter == null ) {
150 throw new NullPointerException("formatter should not be null");
151 }
152 }
153
154 /**
155 * {@inheritDoc}
156 *
157 * @throws SuperCsvCellProcessorException
158 * if value is null or not a Number, or if an invalid decimalFormat String was supplied
159 */
160 public Object execute(final Object value, final CsvContext context) {
161 validateInputNotNull(value, context);
162
163 if( !(value instanceof Number) ) {
164 throw new SuperCsvCellProcessorException(Number.class, value, context, this);
165 }
166
167 // create a new DecimalFormat if one is not supplied
168 final DecimalFormat decimalFormatter;
169 try {
170 decimalFormatter = formatter != null ? formatter : new DecimalFormat(decimalFormat);
171 }
172 catch(IllegalArgumentException e) {
173 throw new SuperCsvCellProcessorException(
174 String.format("'%s' is not a valid decimal format", decimalFormat), context, this, e);
175 }
176
177 final String result = decimalFormatter.format(value);
178 return next.execute(result, context);
179 }
180 }