Add testConnection on JavaMailSender

Add a way to test that a particular JavaMailSender instance can connect
to the server that it is configured for.

Issue: SPR-12799

spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -372,6 +372,21 @@ public class JavaMailSenderImpl implements JavaMailSender {
 		}
 	}
 
+	/**
+	 * Validate that this instance can connect to the server that it is configured
+	 * for. Throws a {@link MessagingException} if the connection attempt failed.
+	 */
+	public void testConnection() throws MessagingException {
+		Transport transport = null;
+		try {
+			transport = connectTransport();
+		}
+		finally {
+			if (transport != null) {
+				transport.close();
+			}
+		}
+	}
 
 	/**
 	 * Actually send the given array of MimeMessages via JavaMail.

spring-context-support/src/test/java/org/springframework/mail/javamail/JavaMailSenderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -35,20 +35,29 @@ import javax.mail.internet.AddressException;
 import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeMessage;
 
-import junit.framework.TestCase;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
 
 import org.springframework.mail.MailParseException;
 import org.springframework.mail.MailSendException;
 import org.springframework.mail.SimpleMailMessage;
 import org.springframework.util.ObjectUtils;
 
+import static org.junit.Assert.*;
+
 /**
  * @author Juergen Hoeller
+ * @author Stephane Nicoll
  * @since 09.10.2004
  */
-public class JavaMailSenderTests extends TestCase {
+public class JavaMailSenderTests {
+
+	@Rule
+	public final ExpectedException thrown = ExpectedException.none();
 
-	public void testJavaMailSenderWithSimpleMessage() throws MessagingException, IOException {
+	@Test
+	public void javaMailSenderWithSimpleMessage() throws MessagingException, IOException {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setPort(30);
@@ -142,7 +151,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(mimeMessage, sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailSenderWithMimeMessages() throws MessagingException {
+	@Test
+	public void javaMailSenderWithMimeMessages() throws MessagingException {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -163,7 +173,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(mimeMessage2, sender.transport.getSentMessage(1));
 	}
 
-	public void testJavaMailSenderWithMimeMessagePreparator() {
+	@Test
+	public void javaMailSenderWithMimeMessagePreparator() {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -188,7 +199,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(messages.get(0), sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailSenderWithMimeMessagePreparators() {
+	@Test
+	public void javaMailSenderWithMimeMessagePreparators() {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -221,7 +233,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(messages.get(1), sender.transport.getSentMessage(1));
 	}
 
-	public void testJavaMailSenderWithMimeMessageHelper() throws MessagingException {
+	@Test
+	public void javaMailSenderWithMimeMessageHelper() throws MessagingException {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -242,7 +255,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(message.getMimeMessage(), sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailSenderWithMimeMessageHelperAndSpecificEncoding() throws MessagingException {
+	@Test
+	public void javaMailSenderWithMimeMessageHelperAndSpecificEncoding() throws MessagingException {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -265,7 +279,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(message.getMimeMessage(), sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailSenderWithMimeMessageHelperAndDefaultEncoding() throws MessagingException {
+	@Test
+	public void javaMailSenderWithMimeMessageHelperAndDefaultEncoding() throws MessagingException {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -289,7 +304,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(message.getMimeMessage(), sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailSenderWithParseExceptionOnSimpleMessage() {
+	@Test
+	public void javaMailSenderWithParseExceptionOnSimpleMessage() {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		SimpleMailMessage simpleMessage = new SimpleMailMessage();
 		simpleMessage.setFrom("");
@@ -302,7 +318,8 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
-	public void testJavaMailSenderWithParseExceptionOnMimeMessagePreparator() {
+	@Test
+	public void javaMailSenderWithParseExceptionOnMimeMessagePreparator() {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		MimeMessagePreparator preparator = new MimeMessagePreparator() {
 			@Override
@@ -319,7 +336,8 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
-	public void testJavaMailSenderWithCustomSession() throws MessagingException {
+	@Test
+	public void javaMailSenderWithCustomSession() throws MessagingException {
 		final Session session = Session.getInstance(new Properties());
 		MockJavaMailSender sender = new MockJavaMailSender() {
 			@Override
@@ -347,7 +365,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(mimeMessage, sender.transport.getSentMessage(0));
 	}
 
-	public void testJavaMailProperties() throws MessagingException {
+	@Test
+	public void javaMailProperties() throws MessagingException {
 		Properties props = new Properties();
 		props.setProperty("bogusKey", "bogusValue");
 		MockJavaMailSender sender = new MockJavaMailSender() {
@@ -374,7 +393,8 @@ public class JavaMailSenderTests extends TestCase {
 		assertEquals(mimeMessage, sender.transport.getSentMessage(0));
 	}
 
-	public void testFailedMailServerConnect() throws Exception {
+	@Test
+	public void failedMailServerConnect() throws Exception {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost(null);
 		sender.setUsername("username");
@@ -394,7 +414,8 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
-	public void testFailedMailServerClose() throws Exception {
+	@Test
+	public void failedMailServerClose() throws Exception {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("");
 		sender.setUsername("username");
@@ -412,7 +433,8 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
-	public void testFailedSimpleMessage() throws Exception {
+	@Test
+	public void failedSimpleMessage() throws Exception {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -443,7 +465,8 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
-	public void testFailedMimeMessage() throws Exception {
+	@Test
+	public void fFailedMimeMessage() throws Exception {
 		MockJavaMailSender sender = new MockJavaMailSender();
 		sender.setHost("host");
 		sender.setUsername("username");
@@ -474,6 +497,22 @@ public class JavaMailSenderTests extends TestCase {
 		}
 	}
 
+	@Test
+	public void testConnection() throws Exception {
+		MockJavaMailSender sender = new MockJavaMailSender();
+		sender.setHost("host");
+		sender.testConnection();
+	}
+
+	@Test
+	public void testConnectionWithFailure() throws Exception {
+		MockJavaMailSender sender = new MockJavaMailSender();
+		sender.setHost(null);
+
+		thrown.expect(MessagingException.class);
+		sender.testConnection();
+	}
+
 
 	private static class MockJavaMailSender extends JavaMailSenderImpl {