| 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 | package org.springframework.batch.core.step.skip; |
| 17 | |
| 18 | import java.io.FileNotFoundException; |
| 19 | import java.util.Collections; |
| 20 | import java.util.Map; |
| 21 | |
| 22 | import org.springframework.batch.classify.BinaryExceptionClassifier; |
| 23 | import org.springframework.batch.classify.Classifier; |
| 24 | import org.springframework.batch.core.Step; |
| 25 | import org.springframework.batch.core.StepExecution; |
| 26 | import org.springframework.batch.item.file.FlatFileParseException; |
| 27 | |
| 28 | /** |
| 29 | * <p> |
| 30 | * {@link SkipPolicy} that determines whether or not reading should continue |
| 31 | * based upon how many items have been skipped. This is extremely useful |
| 32 | * behavior, as it allows you to skip records, but will throw a |
| 33 | * {@link SkipLimitExceededException} if a set limit has been exceeded. For |
| 34 | * example, it is generally advisable to skip {@link FlatFileParseException}s, |
| 35 | * however, if the vast majority of records are causing exceptions, the file is |
| 36 | * likely bad. |
| 37 | * </p> |
| 38 | * |
| 39 | * <p> |
| 40 | * Furthermore, it is also likely that you only want to skip certain exceptions. |
| 41 | * {@link FlatFileParseException} is a good example of an exception you will |
| 42 | * likely want to skip, but a {@link FileNotFoundException} should cause |
| 43 | * immediate termination of the {@link Step}. A {@link Classifier} is used to |
| 44 | * determine whether a particular exception is skippable or not. |
| 45 | * </p> |
| 46 | * |
| 47 | * @author Ben Hale |
| 48 | * @author Lucas Ward |
| 49 | * @author Robert Kasanicky |
| 50 | * @author Dave Syer |
| 51 | * @author Dan Garrette |
| 52 | */ |
| 53 | public class LimitCheckingItemSkipPolicy implements SkipPolicy { |
| 54 | |
| 55 | private int skipLimit; |
| 56 | |
| 57 | private Classifier<Throwable, Boolean> skippableExceptionClassifier; |
| 58 | |
| 59 | /** |
| 60 | * Convenience constructor that assumes all exception types are fatal. |
| 61 | */ |
| 62 | public LimitCheckingItemSkipPolicy() { |
| 63 | this(0, Collections.<Class<? extends Throwable>, Boolean> emptyMap()); |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * @param skipLimit the number of skippable exceptions that are allowed to |
| 68 | * be skipped |
| 69 | * @param skippableExceptions exception classes that can be skipped |
| 70 | * (non-critical) |
| 71 | */ |
| 72 | public LimitCheckingItemSkipPolicy(int skipLimit, Map<Class<? extends Throwable>, Boolean> skippableExceptions) { |
| 73 | this(skipLimit, new BinaryExceptionClassifier(skippableExceptions)); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * @param skipLimit the number of skippable exceptions that are allowed to |
| 78 | * be skipped |
| 79 | * @param skippableExceptionClassifier exception classifier for those that |
| 80 | * can be skipped (non-critical) |
| 81 | */ |
| 82 | public LimitCheckingItemSkipPolicy(int skipLimit, Classifier<Throwable, Boolean> skippableExceptionClassifier) { |
| 83 | this.skipLimit = skipLimit; |
| 84 | this.skippableExceptionClassifier = skippableExceptionClassifier; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * The absolute number of skips (of skippable exceptions) that can be |
| 89 | * tolerated before a failure. |
| 90 | * |
| 91 | * @param skipLimit the skip limit to set |
| 92 | */ |
| 93 | public void setSkipLimit(int skipLimit) { |
| 94 | this.skipLimit = skipLimit; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * The classifier that will be used to decide on skippability. If an |
| 99 | * exception classifies as "true" then it is skippable, and otherwise not. |
| 100 | * |
| 101 | * @param skippableExceptionClassifier the skippableExceptionClassifier to |
| 102 | * set |
| 103 | */ |
| 104 | public void setSkippableExceptionClassifier(Classifier<Throwable, Boolean> skippableExceptionClassifier) { |
| 105 | this.skippableExceptionClassifier = skippableExceptionClassifier; |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * Set up the classifier through a convenient map from throwable class to |
| 110 | * boolean (true if skippable). |
| 111 | * |
| 112 | * @param skippableExceptions the skippable exceptions to set |
| 113 | */ |
| 114 | public void setSkippableExceptionMap(Map<Class<? extends Throwable>, Boolean> skippableExceptions) { |
| 115 | this.skippableExceptionClassifier = new BinaryExceptionClassifier(skippableExceptions); |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Given the provided exception and skip count, determine whether or not |
| 120 | * processing should continue for the given exception. If the exception is |
| 121 | * not classified as skippable in the classifier, false will be returned. If |
| 122 | * the exception is classified as skippable and {@link StepExecution} |
| 123 | * skipCount is greater than the skipLimit, then a |
| 124 | * {@link SkipLimitExceededException} will be thrown. |
| 125 | */ |
| 126 | public boolean shouldSkip(Throwable t, int skipCount) { |
| 127 | if (skippableExceptionClassifier.classify(t)) { |
| 128 | if (skipCount < skipLimit) { |
| 129 | return true; |
| 130 | } |
| 131 | else { |
| 132 | throw new SkipLimitExceededException(skipLimit, t); |
| 133 | } |
| 134 | } |
| 135 | else { |
| 136 | return false; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | } |