1 | package org.springframework.batch.item.transform; |
2 | |
3 | import java.util.Iterator; |
4 | import java.util.List; |
5 | |
6 | import org.springframework.beans.factory.InitializingBean; |
7 | import org.springframework.util.Assert; |
8 | |
9 | /** |
10 | * Composite {@link ItemTransformer} that passes the item through a sequence |
11 | * of injected <code>ItemTransformer</code>s (return value of previous transformation |
12 | * is the entry value of the next). |
13 | * |
14 | * @author Robert Kasanicky |
15 | */ |
16 | public class CompositeItemTransformer implements ItemTransformer, InitializingBean { |
17 | |
18 | private List itemTransformers; |
19 | |
20 | public Object transform(Object item) throws Exception { |
21 | Object result = item; |
22 | for (Iterator iterator = itemTransformers.listIterator(); iterator.hasNext();) { |
23 | result = ((ItemTransformer)iterator.next()).transform(result); |
24 | } |
25 | return result; |
26 | } |
27 | |
28 | public void afterPropertiesSet() throws Exception { |
29 | Assert.notEmpty(itemTransformers); |
30 | for (Iterator iterator = itemTransformers.iterator(); iterator.hasNext();) { |
31 | Assert.isInstanceOf(ItemTransformer.class, iterator.next()); |
32 | } |
33 | } |
34 | |
35 | /** |
36 | * @param itemTransformers will be chained to produce a composite transformation. |
37 | */ |
38 | public void setItemTransformers(List itemTransformers) { |
39 | this.itemTransformers = itemTransformers; |
40 | } |
41 | |
42 | } |