BATCH-1882: Add support for AMQP backed ItemReader / ItemWriter implementations

Add Spring AMQP and Spring Rabbit dependencies. Update
EasyMock from 2.3 to 2.4 to allow for concrete class mocking.

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/amqp/AmqpItemReader.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.batch.item.amqp;
+
+import org.springframework.amqp.core.AmqpTemplate;
+import org.springframework.amqp.core.Message;
+import org.springframework.batch.item.ItemReader;
+import org.springframework.util.Assert;
+
+/**
+ * <p>
+ * AMQP {@link ItemReader} implementation using an {@link AmqpTemplate} to
+ * receive and/or convert messages.
+ * </p>
+ *
+ * @author Chris Schaefer
+ */
+public class AmqpItemReader<T> implements ItemReader<T> {
+    private final AmqpTemplate amqpTemplate;
+    private Class<? extends T> itemType;
+
+    public AmqpItemReader(final AmqpTemplate amqpTemplate) {
+        Assert.notNull(amqpTemplate, "AmpqTemplate must not be null");
+
+        this.amqpTemplate = amqpTemplate;
+    }
+
+    @SuppressWarnings("unchecked")
+    public T read() {
+        if (itemType != null && itemType.isAssignableFrom(Message.class)) {
+            return (T) amqpTemplate.receive();
+        }
+
+        Object result = amqpTemplate.receiveAndConvert();
+
+        if (itemType != null && result != null) {
+            Assert.state(itemType.isAssignableFrom(result.getClass()),
+                    "Received message payload of wrong type: expected [" + itemType + "]");
+        }
+
+        return (T) result;
+    }
+
+    public void setItemType(Class<? extends T> itemType) {
+        Assert.notNull(itemType, "Item type cannot be null");
+        this.itemType = itemType;
+    }
+}

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/amqp/AmqpItemWriter.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.batch.item.amqp;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.amqp.core.AmqpTemplate;
+import org.springframework.batch.item.ItemWriter;
+import org.springframework.util.Assert;
+
+import java.util.List;
+
+/**
+ * <p>
+ * AMQP {@link ItemWriter} implementation using an {@link AmqpTemplate} to
+ * send messages. Messages will be sent to the nameless exchange if not specified
+ * on the provided {@link AmqpTemplate}.
+ * </p>
+ *
+ * @author Chris Schaefer
+ */
+public class AmqpItemWriter<T> implements ItemWriter<T> {
+    private final AmqpTemplate amqpTemplate;
+    private final Log log = LogFactory.getLog(getClass());
+
+    public AmqpItemWriter(final AmqpTemplate amqpTemplate) {
+        Assert.notNull(amqpTemplate, "AmpqTemplate must not be null");
+
+        this.amqpTemplate = amqpTemplate;
+    }
+
+    public void write(final List<? extends T> items) throws Exception {
+        if (log.isDebugEnabled()) {
+            log.debug("Writing to AMQP with " + items.size() + " items.");
+        }
+
+        for (T item : items) {
+            amqpTemplate.convertAndSend(item);
+        }
+    }
+}