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1   /*
2    * Copyright 2006-2013 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.util.Map;
19  
20  import org.springframework.classify.Classifier;
21  import org.springframework.classify.SubclassClassifier;
22  
23  /**
24   * A {@link SkipPolicy} that depends on an exception classifier to make its
25   * decision, and then delegates to the classifier result.
26   *
27   * @author Dave Syer
28   *
29   * @see SubclassClassifier
30   */
31  public class ExceptionClassifierSkipPolicy implements SkipPolicy {
32  
33  	private SubclassClassifier<Throwable, SkipPolicy> classifier;
34  
35  	/**
36  	 * The classifier that will be used to choose a delegate policy.
37  	 *
38  	 * @param classifier the classifier to use to choose a delegate policy
39  	 */
40  	public void setExceptionClassifier(SubclassClassifier<Throwable, SkipPolicy> classifier) {
41  		this.classifier = classifier;
42  	}
43  
44  	/**
45  	 * Setter for policy map. This property should not be changed dynamically -
46  	 * set it once, e.g. in configuration, and then don't change it during a
47  	 * running application. Either this property or the exception classifier
48  	 * directly should be set, but not both.
49  	 *
50  	 * @param policyMap a map of String to {@link SkipPolicy} that will be used
51  	 * to create a {@link Classifier} to locate a policy.
52  	 */
53  	public void setPolicyMap(Map<Class<? extends Throwable>, SkipPolicy> policyMap) {
54  		SubclassClassifier<Throwable, SkipPolicy> subclassClassifier = new SubclassClassifier<Throwable, SkipPolicy>(
55  				policyMap, new NeverSkipItemSkipPolicy());
56  		this.classifier = subclassClassifier;
57  	}
58  
59  	/**
60  	 * Consult the classifier and find a delegate policy, and then use that to
61  	 * determine the outcome.
62  	 *
63  	 * @param t the throwable to consider
64  	 * @param skipCount the current skip count
65  	 * @return true if the exception can be skipped
66  	 * @throws SkipLimitExceededException if a limit is exceeded
67  	 */
68  	@Override
69  	public boolean shouldSkip(Throwable t, int skipCount) throws SkipLimitExceededException {
70  		return classifier.classify(t).shouldSkip(t, skipCount);
71  	}
72  
73  }