INT-3623: Make MailSendingMH More Generic

JIRA: https://jira.spring.io/browse/INT-3623

**Cherry-pick to 4.1.x**

INT-3623: Address PR comments

spring-integration-mail/src/test/java/log4j.properties

@@ -1,4 +1,4 @@
-log4j.rootCategory=DEBUG, stdout
+log4j.rootCategory=WARN, stdout
 
 log4j.appender.stdout=org.apache.log4j.ConsoleAppender
 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

spring-integration-mail/src/test/java/org/springframework/integration/mail/MailSendingMessageHandlerContextTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -16,10 +16,14 @@
 
 package org.springframework.integration.mail;
 
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.DataInputStream;
 
@@ -34,11 +38,12 @@ import org.junit.runner.RunWith;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
-import org.springframework.messaging.MessageChannel;
 import org.springframework.integration.mapping.MessageMappingException;
-import org.springframework.messaging.support.GenericMessage;
 import org.springframework.integration.support.MessageBuilder;
 import org.springframework.mail.SimpleMailMessage;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.MessageHandlingException;
+import org.springframework.messaging.support.GenericMessage;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
@@ -47,7 +52,7 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
  * @author Artem Bilan
  */
 @RunWith(value = SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = {"classpath:/org/springframework/integration/mail/mailSendingMessageHandlerContextTests.xml"})
+@ContextConfiguration
 public class MailSendingMessageHandlerContextTests {
 
 	@Autowired
@@ -57,9 +62,15 @@ public class MailSendingMessageHandlerContextTests {
 	@Autowired
 	private StubJavaMailSender mailSender;
 
+	@Autowired
+	private StubMailSender simpleMailSender;
+
 	@Autowired
 	private MessageChannel sendMailOutboundChainChannel;
 
+	@Autowired
+	private MessageChannel simpleEmailChannel;
+
 	@Autowired
 	private BeanFactory beanFactory;
 
@@ -121,4 +132,47 @@ public class MailSendingMessageHandlerContextTests {
 		assertEquals("message content different from expected", mailMessage, this.mailSender.getSentSimpleMailMessages().get(0));
 	}
 
+	@Test
+	public void testOutboundChannelAdapterWithSimpleMailSender() {
+		this.simpleEmailChannel.send(MailTestsHelper.createIntegrationMessage());
+		assertEquals(1, this.simpleMailSender.getSentMessages().size());
+		assertEquals(MailTestsHelper.createSimpleMailMessage(), this.simpleMailSender.getSentMessages().get(0));
+
+		try {
+			this.simpleEmailChannel.send(new GenericMessage<byte[]>(new byte[0]));
+			fail("IllegalStateException expected");
+		}
+		catch (Exception e) {
+			assertThat(e, instanceOf(MessageHandlingException.class));
+			assertThat(e.getCause(), instanceOf(IllegalStateException.class));
+			assertThat(e.getMessage(), 
+					containsString("this adapter requires a 'JavaMailSender' to send a 'MimeMailMessage'"));
+		}
+
+		try {
+			this.simpleEmailChannel.send(MessageBuilder.withPayload("foo")
+					.setHeader(MailHeaders.CONTENT_TYPE, "text/plain")
+					.setHeader(MailHeaders.TO, "foo@com.foo")
+					.build());
+			fail("IllegalStateException expected");
+		}
+		catch (Exception e) {
+			assertThat(e, instanceOf(MessageHandlingException.class));
+			assertThat(e.getCause(), instanceOf(IllegalStateException.class));
+			assertThat(e.getMessage(), 
+					containsString("this adapter requires a 'JavaMailSender' to send a 'MimeMailMessage'"));
+		}
+
+		try {
+			this.simpleEmailChannel.send(new GenericMessage<MimeMessage>(this.mailSender.createMimeMessage()));
+			fail("IllegalStateException expected");
+		}
+		catch (Exception e) {
+			assertThat(e, instanceOf(MessageHandlingException.class));
+			assertThat(e.getCause(), instanceOf(IllegalStateException.class));
+			assertThat(e.getMessage(), 
+					containsString("this adapter requires a 'JavaMailSender' to send a 'MimeMailMessage'"));
+		}
+	}
+
 }

spring-integration-mail/src/test/java/org/springframework/integration/mail/StubMailSender.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2015 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.integration.mail;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.mail.MailException;
+import org.springframework.mail.MailSender;
+import org.springframework.mail.SimpleMailMessage;
+
+/**
+ * @author Artem Bilan
+ * @since 4.1.3
+ */
+public class StubMailSender implements MailSender {
+
+	private final List<SimpleMailMessage> sentMessages = new ArrayList<SimpleMailMessage>();
+
+	@Override
+	public void send(SimpleMailMessage simpleMessage) throws MailException {
+		this.sentMessages.add(simpleMessage);
+	}
+
+	@Override
+	public void send(SimpleMailMessage... simpleMessages) throws MailException {
+		this.sentMessages.addAll(Arrays.asList(simpleMessages));
+	}
+
+	public List<SimpleMailMessage> getSentMessages() {
+		return this.sentMessages;
+	}
+
+	public void reset() {
+		this.sentMessages.clear();
+	}
+
+}

spring-integration-mail/src/test/java/org/springframework/integration/mail/mailSendingMessageHandlerContextTests-context.xml

@@ -25,4 +25,8 @@
 		<int-mail:outbound-channel-adapter id="mail-outbound-channel-adapter-within-chain" mail-sender="javaMailSender"/>
 	</int:chain>
 
+	<bean id="mailSender" class="org.springframework.integration.mail.StubMailSender"/>
+
+	<int-mail:outbound-channel-adapter id="simpleEmailChannel" mail-sender="mailSender"/>
+
 </beans>