| 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.support; |
| 17 | |
| 18 | import java.util.Comparator; |
| 19 | import java.util.HashMap; |
| 20 | import java.util.Iterator; |
| 21 | import java.util.Map; |
| 22 | import java.util.Set; |
| 23 | import java.util.TreeSet; |
| 24 | |
| 25 | import org.springframework.util.Assert; |
| 26 | |
| 27 | /** |
| 28 | * |
| 29 | * @author Dave Syer |
| 30 | * |
| 31 | */ |
| 32 | public class SubclassExceptionClassifier extends ExceptionClassifierSupport { |
| 33 | |
| 34 | private Map classified = new HashMap(); |
| 35 | |
| 36 | /** |
| 37 | * Map of Throwable class types to keys for the classifier. Any subclass of |
| 38 | * the type provided will be classified as of the type given by the |
| 39 | * corresponding map entry value. |
| 40 | * |
| 41 | * @param typeMap the typeMap to set |
| 42 | */ |
| 43 | public final void setTypeMap(Map typeMap) { |
| 44 | Map map = new HashMap(); |
| 45 | for (Iterator iter = typeMap.entrySet().iterator(); iter.hasNext();) { |
| 46 | Map.Entry entry = (Map.Entry) iter.next(); |
| 47 | addRetryableExceptionClass(entry.getKey(), entry.getValue(), map); |
| 48 | } |
| 49 | this.classified = map; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Return the value from the type map whose key is the class of the given |
| 54 | * Throwable, or its nearest ancestor if a subclass. |
| 55 | * |
| 56 | * @see org.springframework.batch.support.ExceptionClassifierSupport#classify(java.lang.Throwable) |
| 57 | */ |
| 58 | public Object classify(Throwable throwable) { |
| 59 | |
| 60 | if (throwable == null) { |
| 61 | return super.classify(throwable); |
| 62 | } |
| 63 | |
| 64 | Class exceptionClass = throwable.getClass(); |
| 65 | if (classified.containsKey(exceptionClass)) { |
| 66 | return classified.get(exceptionClass); |
| 67 | } |
| 68 | |
| 69 | // check for subclasses |
| 70 | Set classes = new TreeSet(new ClassComparator()); |
| 71 | classes.addAll(classified.keySet()); |
| 72 | for (Iterator iterator = classes.iterator(); iterator.hasNext();) { |
| 73 | Class cls = (Class) iterator.next(); |
| 74 | if (cls.isAssignableFrom(exceptionClass)) { |
| 75 | Object value = classified.get(cls); |
| 76 | addRetryableExceptionClass(exceptionClass, value, this.classified); |
| 77 | return value; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | return super.classify(throwable); |
| 82 | } |
| 83 | |
| 84 | private void addRetryableExceptionClass(Object candidateClass, Object classifiedAs, Map map) { |
| 85 | Assert.isAssignable(Class.class, candidateClass.getClass()); |
| 86 | Class exceptionClass = (Class) candidateClass; |
| 87 | Assert.isAssignable(Throwable.class, exceptionClass); |
| 88 | map.put(exceptionClass, classifiedAs); |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Comparator for classes to order by inheritance. |
| 93 | * |
| 94 | * @author Dave Syer |
| 95 | * |
| 96 | */ |
| 97 | private class ClassComparator implements Comparator { |
| 98 | /** |
| 99 | * @return 1 if arg0 is assignable from arg1, -1 otherwise |
| 100 | * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object) |
| 101 | */ |
| 102 | public int compare(Object arg0, Object arg1) { |
| 103 | Class cls0 = (Class) arg0; |
| 104 | Class cls1 = (Class) arg1; |
| 105 | if (cls0.isAssignableFrom(cls1)) { |
| 106 | return 1; |
| 107 | } |
| 108 | return -1; |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | } |