Add builder for JmsItemReader

resolves BATCH-2602

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/jms/builder/JmsItemReaderBuilder.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2017 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.jms.builder;
+
+import javax.jms.Message;
+
+import org.springframework.batch.item.jms.JmsItemReader;
+import org.springframework.jms.core.JmsOperations;
+import org.springframework.util.Assert;
+
+/**
+ * Creates a fully qualified JmsItemReader.
+ *
+ * @author Glenn Renfro
+ *
+ * @since 4.0
+ */
+public class JmsItemReaderBuilder<T> {
+
+	protected Class<? extends T> itemType;
+
+	protected JmsOperations jmsTemplate;
+
+	/**
+	 * Establish the JMS template that will be used by the JmsItemReader.
+	 *
+	 * @param jmsTemplate a {@link JmsOperations} instance
+	 * @return this instance for method chaining.
+	 * @see JmsItemReader#setJmsTemplate(JmsOperations)
+	 */
+	public JmsItemReaderBuilder<T> jmsTemplate(JmsOperations jmsTemplate) {
+		this.jmsTemplate = jmsTemplate;
+
+		return this;
+	}
+
+	/**
+	 * Set the expected type of incoming message payloads. Set this to {@link Message} to
+	 * receive the raw underlying message.
+	 *
+	 * @param itemType the java class of the items to be delivered. Typically the same as
+	 * the class parameter
+	 * @return this instance for method chaining.
+	 *
+	 * @throws IllegalStateException if the message payload is of the wrong type.
+	 * @see JmsItemReader#setItemType(Class)
+	 */
+	public JmsItemReaderBuilder<T> itemType(Class<? extends T> itemType) {
+		this.itemType = itemType;
+
+		return this;
+	}
+
+	/**
+	 * Returns a fully constructed {@link JmsItemReader}.
+	 *
+	 * @return a new {@link JmsItemReader}
+	 */
+	public JmsItemReader<T> build() {
+		Assert.notNull(this.jmsTemplate, "jmsTemplate is required.");
+		JmsItemReader<T> jmsItemReader = new JmsItemReader<>();
+
+		jmsItemReader.setItemType(this.itemType);
+		jmsItemReader.setJmsTemplate(this.jmsTemplate);
+		return jmsItemReader;
+	}
+}