Add reflection check for Spring 4.1 in Mail Writer tests

As part of the Spring Framework 4.1 updates, the send methods on both
MailSender#send and JavaMailSender#send were converted from taking an
array to vargs.  This commit adds a reflection check to determine which
version of Spring it's being built against and uses the apropriate
mocking checks in these tests based on that check.

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

@@ -17,6 +17,7 @@ package org.springframework.batch.item.mail;
 
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import static org.mockito.AdditionalMatchers.aryEq;
 
@@ -28,11 +29,13 @@ import javax.mail.MessagingException;
 
 import org.junit.Before;
 import org.junit.Test;
+
 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 org.springframework.util.ReflectionUtils;
 
 /**
  * @author Dave Syer
@@ -59,11 +62,15 @@ public class SimpleMailMessageItemWriterTests {
 		SimpleMailMessage bar = new SimpleMailMessage();
 		SimpleMailMessage[] items = new SimpleMailMessage[] { foo, bar };
 
-		mailSender.send(aryEq(items));
-
 		writer.write(Arrays.asList(items));
 
-
+		// Spring 4.1 changed the send method to be vargs instead of an array
+		if(ReflectionUtils.findMethod(SimpleMailMessage.class, "send", SimpleMailMessage[].class) != null) {
+			verify(mailSender).send(aryEq(items));
+		}
+		else {
+			verify(mailSender).send(items);
+		}
 	}
 
 	@Test(expected = MailSendException.class)
@@ -73,11 +80,17 @@ public class SimpleMailMessageItemWriterTests {
 		SimpleMailMessage bar = new SimpleMailMessage();
 		SimpleMailMessage[] items = new SimpleMailMessage[] { foo, bar };
 
-		mailSender.send(aryEq(items));
+		// Spring 4.1 changed the send method to be vargs instead of an array
+		if(ReflectionUtils.findMethod(SimpleMailMessage.class, "send", SimpleMailMessage[].class) != null) {
+			mailSender.send(aryEq(items));
+		}
+		else {
+			mailSender.send(items);
+		}
+
 		when(mailSender).thenThrow(new MailSendException(Collections.singletonMap((Object)foo, (Exception)new MessagingException("FOO"))));
 
 		writer.write(Arrays.asList(items));
-
 	}
 
 	@Test
@@ -95,14 +108,19 @@ public class SimpleMailMessageItemWriterTests {
 		SimpleMailMessage bar = new SimpleMailMessage();
 		SimpleMailMessage[] items = new SimpleMailMessage[] { foo, bar };
 
-		mailSender.send(aryEq(items));
+		// Spring 4.1 changed the send method to be vargs instead of an array
+		if(ReflectionUtils.findMethod(SimpleMailMessage.class, "send", SimpleMailMessage[].class) != null) {
+			mailSender.send(aryEq(items));
+		}
+		else {
+			mailSender.send(items);
+		}
+
 		when(mailSender).thenThrow(new MailSendException(Collections.singletonMap((Object)foo, (Exception)new MessagingException("FOO"))));
 
 		writer.write(Arrays.asList(items));
 
 		assertEquals("FOO", content.get());
-
-
 	}
 
 }

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/mail/javamail/MimeMessageItemWriterTests.java

@@ -35,7 +35,9 @@ import org.springframework.batch.item.mail.MailErrorHandler;
 import org.springframework.mail.MailException;
 import org.springframework.mail.MailMessage;
 import org.springframework.mail.MailSendException;
+import org.springframework.mail.MailSender;
 import org.springframework.mail.javamail.JavaMailSender;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * @author Dave Syer
@@ -78,12 +80,17 @@ public class MimeMessageItemWriterTests {
 		MimeMessage bar = new MimeMessage(session);
 		MimeMessage[] items = new MimeMessage[] { foo, bar };
 
-		mailSender.send(aryEq(items));
+		// Spring 4.1 changed the send method to be vargs instead of an array
+		if(ReflectionUtils.findMethod(MailSender.class, "send", MimeMessage[].class) != null) {
+			mailSender.send(aryEq(items));
+		}
+		else {
+			mailSender.send(items);
+		}
+
 		when(mailSender).thenThrow(new MailSendException(Collections.singletonMap((Object)foo, (Exception)new MessagingException("FOO"))));
 
 		writer.write(Arrays.asList(items));
-
-
 	}
 
 	@Test
@@ -101,7 +108,15 @@ public class MimeMessageItemWriterTests {
 		MimeMessage bar = new MimeMessage(session);
 		MimeMessage[] items = new MimeMessage[] { foo, bar };
 
-		mailSender.send(aryEq(items));
+
+		// Spring 4.1 changed the send method to be vargs instead of an array
+		if(ReflectionUtils.findMethod(MailSender.class, "send", MimeMessage[].class) != null) {
+			mailSender.send(aryEq(items));
+		}
+		else {
+			mailSender.send(items);
+		}
+
 		when(mailSender).thenThrow(new MailSendException(Collections.singletonMap((Object)foo, (Exception)new MessagingException("FOO"))));
 
 		writer.write(Arrays.asList(items));