| 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.classify; |
| 17 | |
| 18 | import java.util.Map; |
| 19 | |
| 20 | /** |
| 21 | * A special purpose {@link Classifier} with easy configuration options for |
| 22 | * mapping from one arbitrary type of object to another via a pattern matcher. |
| 23 | * |
| 24 | * @author Dave Syer |
| 25 | * |
| 26 | */ |
| 27 | public class BackToBackPatternClassifier<C, T> implements Classifier<C, T> { |
| 28 | |
| 29 | private Classifier<C, String> router; |
| 30 | |
| 31 | private Classifier<String, T> matcher; |
| 32 | |
| 33 | /** |
| 34 | * Default constructor, provided as a convenience for people using setter |
| 35 | * injection. |
| 36 | */ |
| 37 | public BackToBackPatternClassifier() { |
| 38 | } |
| 39 | |
| 40 | /** |
| 41 | * Set up a classifier with input to the router and output from the matcher. |
| 42 | * |
| 43 | * @param router see {@link #setRouterDelegate(Object)} |
| 44 | * @param matcher see {@link #setMatcherMap(Map)} |
| 45 | */ |
| 46 | public BackToBackPatternClassifier(Classifier<C, String> router, Classifier<String, T> matcher) { |
| 47 | super(); |
| 48 | this.router = router; |
| 49 | this.matcher = matcher; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * A convenience method for creating a pattern matching classifier for the |
| 54 | * matcher component. |
| 55 | * |
| 56 | * @param map maps pattern keys with wildcards to output values |
| 57 | */ |
| 58 | public void setMatcherMap(Map<String, T> map) { |
| 59 | this.matcher = new PatternMatchingClassifier<T>(map); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * A convenience method of creating a router classifier based on a plain old |
| 64 | * Java Object. The object provided must have precisely one public method |
| 65 | * that either has the @Classifier annotation or accepts a single argument |
| 66 | * and outputs a String. This will be used to create an input classifier for |
| 67 | * the router component. <br/> |
| 68 | * |
| 69 | * @param delegate the delegate object used to create a router classifier |
| 70 | */ |
| 71 | public void setRouterDelegate(Object delegate) { |
| 72 | this.router = new ClassifierAdapter<C,String>(delegate); |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * Classify the input and map to a String, then take that and put it into a |
| 77 | * pattern matcher to match to an output value. |
| 78 | */ |
| 79 | public T classify(C classifiable) { |
| 80 | return matcher.classify(router.classify(classifiable)); |
| 81 | } |
| 82 | |
| 83 | } |