| 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 | |
| 17 | package org.springframework.batch.item.jms; |
| 18 | |
| 19 | import javax.jms.JMSException; |
| 20 | import javax.jms.Message; |
| 21 | |
| 22 | import org.springframework.batch.item.UnexpectedInputException; |
| 23 | import org.springframework.retry.interceptor.MethodArgumentsKeyGenerator; |
| 24 | |
| 25 | /** |
| 26 | * A {@link MethodArgumentsKeyGenerator} for JMS |
| 27 | * |
| 28 | * @author Dave Syer |
| 29 | * |
| 30 | */ |
| 31 | public class JmsMethodArgumentsKeyGenerator implements MethodArgumentsKeyGenerator { |
| 32 | |
| 33 | /** |
| 34 | * If the message is a {@link Message} then returns the JMS message ID. |
| 35 | * Otherwise just return the first argument. |
| 36 | * |
| 37 | * @see org.springframework.retry.interceptor.MethodArgumentsKeyGenerator#getKey(Object[]) |
| 38 | * |
| 39 | * @throws UnexpectedInputException if the JMS id cannot be determined from |
| 40 | * a JMS Message |
| 41 | * @throws IllegalArgumentException if the arguments are empty |
| 42 | */ |
| 43 | @Override |
| 44 | public Object getKey(Object[] items) { |
| 45 | for (Object item : items) { |
| 46 | if (item instanceof Message) { |
| 47 | try { |
| 48 | return ((Message) item).getJMSMessageID(); |
| 49 | } |
| 50 | catch (JMSException e) { |
| 51 | throw new UnexpectedInputException("Could not extract message ID", e); |
| 52 | } |
| 53 | } |
| 54 | } |
| 55 | if (items.length == 0) { |
| 56 | throw new IllegalArgumentException( |
| 57 | "Method parameters are empty. The key generator cannot determine a unique key."); |
| 58 | } |
| 59 | return items[0]; |
| 60 | } |
| 61 | |
| 62 | } |