| 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.core.step.item; |
| 18 | |
| 19 | import org.springframework.batch.classify.BinaryExceptionClassifier; |
| 20 | import org.springframework.batch.classify.Classifier; |
| 21 | import org.springframework.batch.core.StepContribution; |
| 22 | import org.springframework.batch.core.step.skip.LimitCheckingItemSkipPolicy; |
| 23 | import org.springframework.batch.core.step.skip.NonSkippableReadException; |
| 24 | import org.springframework.batch.core.step.skip.SkipListenerFailedException; |
| 25 | import org.springframework.batch.core.step.skip.SkipPolicy; |
| 26 | import org.springframework.batch.item.ItemReader; |
| 27 | import org.springframework.batch.repeat.RepeatOperations; |
| 28 | |
| 29 | /** |
| 30 | * FaultTolerant implementation of the {@link ChunkProcessor} interface, that |
| 31 | * allows for skipping or retry of items that cause exceptions during reading or |
| 32 | * processing. |
| 33 | * |
| 34 | */ |
| 35 | public class FaultTolerantChunkProvider<I> extends SimpleChunkProvider<I> { |
| 36 | |
| 37 | private SkipPolicy skipPolicy = new LimitCheckingItemSkipPolicy(0); |
| 38 | |
| 39 | private Classifier<Throwable, Boolean> rollbackClassifier = new BinaryExceptionClassifier(true); |
| 40 | |
| 41 | public FaultTolerantChunkProvider(ItemReader<? extends I> itemReader, RepeatOperations repeatOperations) { |
| 42 | super(itemReader, repeatOperations); |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * The policy that determines whether exceptions can be skipped on read. |
| 47 | * @param SkipPolicy |
| 48 | */ |
| 49 | public void setSkipPolicy(SkipPolicy SkipPolicy) { |
| 50 | this.skipPolicy = SkipPolicy; |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * Classifier to determine whether exceptions have been marked as |
| 55 | * no-rollback (as opposed to skippable). If ecnounterd they are simply |
| 56 | * ignored, unless also skippable. |
| 57 | * |
| 58 | * @param rollbackClassifier the rollback classifier to set |
| 59 | */ |
| 60 | public void setRollbackClassifier(Classifier<Throwable, Boolean> rollbackClassifier) { |
| 61 | this.rollbackClassifier = rollbackClassifier; |
| 62 | } |
| 63 | |
| 64 | @Override |
| 65 | protected I read(StepContribution contribution, Chunk<I> chunk) throws Exception { |
| 66 | while (true) { |
| 67 | try { |
| 68 | return doRead(); |
| 69 | } |
| 70 | catch (Exception e) { |
| 71 | |
| 72 | if (skipPolicy.shouldSkip(e, contribution.getStepSkipCount())) { |
| 73 | // increment skip count and try again |
| 74 | contribution.incrementReadSkipCount(); |
| 75 | chunk.skip(e); |
| 76 | |
| 77 | logger.debug("Skipping failed input", e); |
| 78 | } |
| 79 | else { |
| 80 | if (rollbackClassifier.classify(e)) { |
| 81 | throw new NonSkippableReadException("Non-skippable exception during read", e); |
| 82 | } |
| 83 | logger.debug("No-rollback for non-skippable exception (ignored)", e); |
| 84 | } |
| 85 | |
| 86 | } |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | @Override |
| 91 | public void postProcess(StepContribution contribution, Chunk<I> chunk) { |
| 92 | for (Exception e : chunk.getErrors()) { |
| 93 | try { |
| 94 | getListener().onSkipInRead(e); |
| 95 | } |
| 96 | catch (RuntimeException ex) { |
| 97 | throw new SkipListenerFailedException("Fatal exception in SkipListener.", ex, e); |
| 98 | } |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | } |