| 1 | /* |
| 2 | * Copyright 2012-2013 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 | |
| 17 | package org.springframework.batch.item.amqp; |
| 18 | |
| 19 | import org.springframework.amqp.core.AmqpTemplate; |
| 20 | import org.springframework.amqp.core.Message; |
| 21 | import org.springframework.batch.item.ItemReader; |
| 22 | import org.springframework.util.Assert; |
| 23 | |
| 24 | /** |
| 25 | * <p> |
| 26 | * AMQP {@link ItemReader} implementation using an {@link AmqpTemplate} to |
| 27 | * receive and/or convert messages. |
| 28 | * </p> |
| 29 | * |
| 30 | * @author Chris Schaefer |
| 31 | */ |
| 32 | public class AmqpItemReader<T> implements ItemReader<T> { |
| 33 | private final AmqpTemplate amqpTemplate; |
| 34 | private Class<? extends T> itemType; |
| 35 | |
| 36 | public AmqpItemReader(final AmqpTemplate amqpTemplate) { |
| 37 | Assert.notNull(amqpTemplate, "AmpqTemplate must not be null"); |
| 38 | |
| 39 | this.amqpTemplate = amqpTemplate; |
| 40 | } |
| 41 | |
| 42 | @Override |
| 43 | @SuppressWarnings("unchecked") |
| 44 | public T read() { |
| 45 | if (itemType != null && itemType.isAssignableFrom(Message.class)) { |
| 46 | return (T) amqpTemplate.receive(); |
| 47 | } |
| 48 | |
| 49 | Object result = amqpTemplate.receiveAndConvert(); |
| 50 | |
| 51 | if (itemType != null && result != null) { |
| 52 | Assert.state(itemType.isAssignableFrom(result.getClass()), |
| 53 | "Received message payload of wrong type: expected [" + itemType + "]"); |
| 54 | } |
| 55 | |
| 56 | return (T) result; |
| 57 | } |
| 58 | |
| 59 | public void setItemType(Class<? extends T> itemType) { |
| 60 | Assert.notNull(itemType, "Item type cannot be null"); |
| 61 | this.itemType = itemType; |
| 62 | } |
| 63 | } |