| 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.retry.callback; |
| 18 | |
| 19 | import org.springframework.batch.item.FailedItemIdentifier; |
| 20 | import org.springframework.batch.item.ItemKeyGenerator; |
| 21 | import org.springframework.batch.item.ItemRecoverer; |
| 22 | import org.springframework.batch.item.ItemWriter; |
| 23 | import org.springframework.batch.retry.RetryCallback; |
| 24 | import org.springframework.batch.retry.RetryContext; |
| 25 | import org.springframework.batch.retry.RetryException; |
| 26 | import org.springframework.batch.retry.RetryPolicy; |
| 27 | import org.springframework.batch.retry.policy.ItemWriterRetryPolicy; |
| 28 | |
| 29 | /** |
| 30 | * A {@link RetryCallback} that knows about and caches an item, and attempts to |
| 31 | * process it using an {@link ItemWriter}. Used by the |
| 32 | * {@link ItemWriterRetryPolicy} to enable external retry of the item |
| 33 | * processing. |
| 34 | * |
| 35 | * @author Dave Syer |
| 36 | * |
| 37 | * @see ItemWriterRetryPolicy |
| 38 | * @see RetryPolicy#handleRetryExhausted(RetryContext) |
| 39 | * |
| 40 | */ |
| 41 | public class ItemWriterRetryCallback implements RetryCallback { |
| 42 | |
| 43 | private Object item; |
| 44 | |
| 45 | private ItemWriter writer; |
| 46 | |
| 47 | private ItemRecoverer recoverer; |
| 48 | |
| 49 | private ItemKeyGenerator keyGenerator; |
| 50 | |
| 51 | private FailedItemIdentifier failedItemIdentifier; |
| 52 | |
| 53 | private ItemKeyGenerator defaultKeyGenerator = new ItemKeyGenerator() { |
| 54 | public Object getKey(Object item) { |
| 55 | return item; |
| 56 | } |
| 57 | }; |
| 58 | |
| 59 | /** |
| 60 | * Constructor with mandatory properties. |
| 61 | * |
| 62 | * @param item the item to process |
| 63 | * @param writer the writer to use to process it |
| 64 | */ |
| 65 | public ItemWriterRetryCallback(Object item, ItemWriter writer) { |
| 66 | super(); |
| 67 | this.item = item; |
| 68 | this.writer = writer; |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Setter for injecting optional recovery handler. If it is not injected but |
| 73 | * the reader or writer implement {@link ItemRecoverer}, one of those will |
| 74 | * be used instead (preferring the reader to the writer if both would be |
| 75 | * appropriate). |
| 76 | * |
| 77 | * @param recoverer |
| 78 | */ |
| 79 | public void setRecoverer(ItemRecoverer recoverer) { |
| 80 | this.recoverer = recoverer; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Public setter for the {@link ItemKeyGenerator}. If it is not injected |
| 85 | * but the reader or writer implement {@link ItemKeyGenerator}, one of |
| 86 | * those will be used instead (preferring the reader to the writer if both |
| 87 | * would be appropriate). |
| 88 | * @param keyGenerator the keyGenerator to set |
| 89 | */ |
| 90 | public void setKeyGenerator(ItemKeyGenerator keyGenerator) { |
| 91 | this.keyGenerator = keyGenerator; |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Public setter for the {@link FailedItemIdentifier}. If it is not |
| 96 | * injected but the reader or writer implement {@link FailedItemIdentifier}, |
| 97 | * one of those will be used instead (preferring the reader to the writer if |
| 98 | * both would be appropriate). |
| 99 | * @param failedItemIdentifier the {@link FailedItemIdentifier} to set |
| 100 | */ |
| 101 | public void setFailedItemIdentifier(FailedItemIdentifier failedItemIdentifier) { |
| 102 | this.failedItemIdentifier = failedItemIdentifier; |
| 103 | } |
| 104 | |
| 105 | public Object doWithRetry(RetryContext context) throws Throwable { |
| 106 | // This requires a collaboration with the RetryPolicy... |
| 107 | if (!context.isExhaustedOnly()) { |
| 108 | if (item != null) { |
| 109 | writer.write(item); |
| 110 | } |
| 111 | return null; |
| 112 | } |
| 113 | throw new RetryException("Recovery path requested in retry callback."); |
| 114 | } |
| 115 | |
| 116 | public Object getItem() { |
| 117 | return item; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Accessor for the {@link ItemRecoverer}. If the handler is null but the |
| 122 | * {@link ItemWriter} is an instance of {@link ItemRecoverer}, then it will |
| 123 | * be returned instead. If none of those strategies works then a default |
| 124 | * implementation of {@link ItemKeyGenerator} will be used that just returns |
| 125 | * the item. |
| 126 | * |
| 127 | * @return the {@link ItemRecoverer}. |
| 128 | */ |
| 129 | public ItemKeyGenerator getKeyGenerator() { |
| 130 | if (keyGenerator != null) { |
| 131 | return keyGenerator; |
| 132 | } |
| 133 | if (writer instanceof ItemKeyGenerator) { |
| 134 | return (ItemKeyGenerator) writer; |
| 135 | } |
| 136 | return defaultKeyGenerator; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Accessor for the {@link FailedItemIdentifier}. If the handler is null |
| 141 | * but the {@link ItemWriter} or {@link ItemWriter} is an instance of |
| 142 | * {@link FailedItemIdentifier}, then it will be returned instead. If none |
| 143 | * of those strategies works returns null. |
| 144 | * |
| 145 | * @return the {@link FailedItemIdentifier}. |
| 146 | */ |
| 147 | public FailedItemIdentifier getFailedItemIdentifier() { |
| 148 | if (failedItemIdentifier != null) { |
| 149 | return failedItemIdentifier; |
| 150 | } |
| 151 | if (writer instanceof FailedItemIdentifier) { |
| 152 | return (FailedItemIdentifier) writer; |
| 153 | } |
| 154 | return null; |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * Accessor for the {@link ItemRecoverer}. If the handler is null but the |
| 159 | * {@link ItemWriter} is an instance of {@link ItemRecoverer}, then it will |
| 160 | * be returned instead. |
| 161 | * |
| 162 | * @return the {@link ItemRecoverer}. |
| 163 | */ |
| 164 | public ItemRecoverer getRecoverer() { |
| 165 | if (recoverer != null) { |
| 166 | return recoverer; |
| 167 | } |
| 168 | if (writer instanceof ItemRecoverer) { |
| 169 | return (ItemRecoverer) writer; |
| 170 | } |
| 171 | return null; |
| 172 | } |
| 173 | |
| 174 | } |