| 1 | /* |
| 2 | * Copyright 2006-2007 the original author or authors. |
| 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 | |
| 17 | package org.springframework.batch.item.file.transform; |
| 18 | |
| 19 | import java.util.Formatter; |
| 20 | import java.util.Locale; |
| 21 | |
| 22 | import org.springframework.util.Assert; |
| 23 | |
| 24 | /** |
| 25 | * A {@link LineAggregator} implementation which produces a String by |
| 26 | * aggregating the provided item via the {@link Formatter} syntax.</br> |
| 27 | * |
| 28 | * @see Formatter |
| 29 | * |
| 30 | * @author Dave Syer |
| 31 | */ |
| 32 | public class FormatterLineAggregator<T> extends ExtractorLineAggregator<T> { |
| 33 | |
| 34 | private String format; |
| 35 | |
| 36 | private Locale locale = Locale.getDefault(); |
| 37 | |
| 38 | private int maximumLength = 0; |
| 39 | |
| 40 | private int minimumLength = 0; |
| 41 | |
| 42 | /** |
| 43 | * Public setter for the minimum length of the formatted string. If this is |
| 44 | * not set the default is to allow any length. |
| 45 | * |
| 46 | * @param minimumLength the minimum length to set |
| 47 | */ |
| 48 | public void setMinimumLength(int minimumLength) { |
| 49 | this.minimumLength = minimumLength; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Public setter for the maximum length of the formatted string. If this is |
| 54 | * not set the default is to allow any length. |
| 55 | * @param maximumLength the maximum length to set |
| 56 | */ |
| 57 | public void setMaximumLength(int maximumLength) { |
| 58 | this.maximumLength = maximumLength; |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * Set the format string used to aggregate items. |
| 63 | * |
| 64 | * @see Formatter |
| 65 | */ |
| 66 | public void setFormat(String format) { |
| 67 | this.format = format; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Public setter for the locale. |
| 72 | * @param locale the locale to set |
| 73 | */ |
| 74 | public void setLocale(Locale locale) { |
| 75 | this.locale = locale; |
| 76 | } |
| 77 | |
| 78 | @Override |
| 79 | protected String doAggregate(Object[] fields) { |
| 80 | |
| 81 | Assert.notNull(format); |
| 82 | |
| 83 | String value = String.format(locale, format, fields); |
| 84 | |
| 85 | if (maximumLength > 0) { |
| 86 | Assert.state(value.length() <= maximumLength, String.format("String overflowed in formatter -" |
| 87 | + " longer than %d characters: [%s", maximumLength, value)); |
| 88 | } |
| 89 | |
| 90 | if (minimumLength > 0) { |
| 91 | Assert.state(value.length() >= minimumLength, String.format("String underflowed in formatter -" |
| 92 | + " shorter than %d characters: [%s", minimumLength, value)); |
| 93 | } |
| 94 | |
| 95 | return value; |
| 96 | } |
| 97 | } |