Adds Builder for SimpleMailMessageItemWriter

resolves BATCH-2594

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/builder/JpaPagingItemReaderBuilder.java

@@ -23,8 +23,13 @@ import org.springframework.batch.item.database.orm.JpaQueryProvider;
 import org.springframework.util.Assert;
 
 /**
+ * Creates a fully qualified JpaPagingItemReader.
+ *
  * @author Michael Minella
+ *
+ * @since 4.0
  */
+
 public class JpaPagingItemReaderBuilder<T> {
 
 	private String name;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/mail/builder/SimpleMailMessageItemWriterBuilder.java

@@ -0,0 +1,82 @@
+/*
+ * 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.mail.builder;
+
+import java.util.List;
+
+import org.springframework.batch.item.mail.DefaultMailErrorHandler;
+import org.springframework.batch.item.mail.MailErrorHandler;
+import org.springframework.batch.item.mail.SimpleMailMessageItemWriter;
+import org.springframework.mail.MailSender;
+import org.springframework.util.Assert;
+
+/**
+ * Creates a fully qualified SimpleMailMessageItemWriter.
+ *
+ * @author Glenn Renfro
+ *
+ * @since 4.0
+ */
+
+public class SimpleMailMessageItemWriterBuilder {
+
+	private MailSender mailSender;
+
+	private MailErrorHandler mailErrorHandler = new DefaultMailErrorHandler();
+
+	/**
+	 * A {@link MailSender} to be used to send messages in
+	 * {@link SimpleMailMessageItemWriter#write(List)}.
+	 *
+	 * @param mailSender strategy for sending simple mails.
+	 * @return this instance for method chaining.
+	 * @see SimpleMailMessageItemWriter#setMailSender(MailSender)
+	 */
+	public SimpleMailMessageItemWriterBuilder mailSender(MailSender mailSender) {
+		this.mailSender = mailSender;
+		return this;
+	}
+
+	/**
+	 * The handler for failed messages. Defaults to a {@link DefaultMailErrorHandler}.
+	 *
+	 * @param mailErrorHandler the mail error handler to set.
+	 * @return this instance for method chaining.
+	 * @see SimpleMailMessageItemWriter#setMailErrorHandler(MailErrorHandler)
+	 */
+	public SimpleMailMessageItemWriterBuilder mailErrorHandler(MailErrorHandler mailErrorHandler) {
+		this.mailErrorHandler = mailErrorHandler;
+		return this;
+	}
+
+	/**
+	 * Returns a fully constructed {@link SimpleMailMessageItemWriter}.
+	 *
+	 * @return a new {@link SimpleMailMessageItemWriter}
+	 */
+	public SimpleMailMessageItemWriter build() {
+		Assert.notNull(this.mailSender, "A mailSender is required");
+
+		SimpleMailMessageItemWriter writer = new SimpleMailMessageItemWriter();
+		writer.setMailSender(this.mailSender);
+		if (mailErrorHandler != null) {
+			writer.setMailErrorHandler(this.mailErrorHandler);
+		}
+
+		return writer;
+	}
+}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/mail/builder/SimpleMailMessageItemWriterBuilderTests.java

@@ -0,0 +1,112 @@
+/*
+ * 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.mail.builder;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.concurrent.atomic.AtomicReference;
+
+import javax.mail.MessagingException;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.batch.item.mail.MailErrorHandler;
+import org.springframework.batch.item.mail.SimpleMailMessageItemWriter;
+import org.springframework.mail.MailException;
+import org.springframework.mail.MailMessage;
+import org.springframework.mail.MailSendException;
+import org.springframework.mail.MailSender;
+import org.springframework.mail.SimpleMailMessage;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * @author Glenn Renfro
+ */
+public class SimpleMailMessageItemWriterBuilderTests {
+
+	private MailSender mailSender;
+
+	private SimpleMailMessage foo;
+
+	private SimpleMailMessage bar;
+
+	private SimpleMailMessage[] items;
+
+	@Before
+	public void setup() {
+		mailSender = mock(MailSender.class);
+		this.foo = new SimpleMailMessage();
+		this.bar = new SimpleMailMessage();
+		this.items = new SimpleMailMessage[] { this.foo, this.bar };
+	}
+
+	@Test
+	public void testSend() throws Exception {
+		SimpleMailMessageItemWriter writer = new SimpleMailMessageItemWriterBuilder().mailSender(this.mailSender)
+				.build();
+
+		writer.write(Arrays.asList(this.items));
+		verify(this.mailSender).send(this.foo, this.bar);
+	}
+
+	@Test
+	public void testMailSenderNotSet() throws Exception {
+		try {
+			new SimpleMailMessageItemWriterBuilder().build();
+			fail("A mailSender is required");
+		}
+		catch (IllegalArgumentException iae) {
+			assertEquals("A mailSender is required", iae.getMessage());
+		}
+	}
+
+	@Test(expected = MailSendException.class)
+	public void testErrorHandler() throws Exception {
+		SimpleMailMessageItemWriter writer = new SimpleMailMessageItemWriterBuilder().mailSender(this.mailSender)
+				.build();
+
+		this.mailSender.send(this.foo, this.bar);
+		when(this.mailSender)
+				.thenThrow(new MailSendException(Collections.singletonMap(this.foo, new MessagingException("FOO"))));
+		writer.write(Arrays.asList(this.items));
+	}
+
+	@Test
+	public void testCustomErrorHandler() throws Exception {
+		final AtomicReference<String> content = new AtomicReference<String>();
+		SimpleMailMessageItemWriter writer = new SimpleMailMessageItemWriterBuilder()
+				.mailErrorHandler(new MailErrorHandler() {
+					@Override
+					public void handle(MailMessage message, Exception exception) throws MailException {
+						content.set(exception.getMessage());
+					}
+				}).mailSender(this.mailSender).build();
+
+		this.mailSender.send(this.foo, this.bar);
+		when(this.mailSender)
+				.thenThrow(new MailSendException(Collections.singletonMap(this.foo, new MessagingException("FOO"))));
+		writer.write(Arrays.asList(this.items));
+		assertEquals("FOO", content.get());
+	}
+
+}