INT-1701 added reconnect logic to ImapIdleChannelAdapter

spring-integration-mail/src/main/java/org/springframework/integration/mail/AbstractMailReceiver.java

@@ -303,4 +303,8 @@ public abstract class AbstractMailReceiver extends IntegrationObjectSupport impl
 			this.folderOpenMode = Folder.READ_WRITE;
 		}
 	}
+	
+	Store getStore(){
+		return this.store;
+	}
 }

spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapIdleChannelAdapter.java

@@ -16,11 +16,15 @@
 
 package org.springframework.integration.mail;
 
+import java.net.UnknownHostException;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
 
 import javax.mail.FolderClosedException;
 import javax.mail.Message;
 import javax.mail.MessagingException;
+import javax.mail.StoreClosedException;
 import javax.mail.internet.MimeMessage;
 
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
@@ -47,6 +51,10 @@ public class ImapIdleChannelAdapter extends MessageProducerSupport {
 	private volatile Executor taskExecutor;
 
 	private final ImapMailReceiver mailReceiver;
+	
+	private volatile boolean reconnecting;
+	
+	private volatile int reconnectDelay = 10; // seconds
 
 
 	public ImapIdleChannelAdapter(ImapMailReceiver mailReceiver) {
@@ -117,6 +125,7 @@ public class ImapIdleChannelAdapter extends MessageProducerSupport {
 						logger.debug("waiting for mail");
 					}
 					mailReceiver.waitForNewMessages();
+					reconnecting = false;
 					Message[] mailMessages = mailReceiver.receive();
 					if (logger.isDebugEnabled()) {
 						logger.debug("received " + mailMessages.length + " mail messages");
@@ -127,8 +136,13 @@ public class ImapIdleChannelAdapter extends MessageProducerSupport {
 					}
 				}
 				catch (MessagingException e) {
-					if (e instanceof FolderClosedException && shouldReconnectAutomatically) {
-						continue;
+					if (shouldReconnectAutomatically){
+						if (e instanceof FolderClosedException || 
+							e instanceof StoreClosedException || 
+							(e.getNextException() instanceof UnknownHostException && reconnecting)){
+							waitToReconnect();
+							continue;
+						}
 					}
 					handleMailMessagingException(e);
 					return;
@@ -144,4 +158,14 @@ public class ImapIdleChannelAdapter extends MessageProducerSupport {
 		return "mail:imap-idle-channel-adapter";
 	}
 
+	private void waitToReconnect() {
+		CountDownLatch latch = new CountDownLatch(1);
+		try {
+			logger.warn("Waiting " + reconnectDelay + " seconds before attemptong to reconnect to host");
+			latch.await(5, TimeUnit.SECONDS);
+			reconnecting = true;
+			logger.warn("Will attempt to reconnect to host now");
+		} catch (Exception ignore) {
+		}
+	}
 }

spring-integration-mail/src/main/java/org/springframework/integration/mail/ImapMailReceiver.java

@@ -21,6 +21,7 @@ import javax.mail.Flags.Flag;
 import javax.mail.Folder;
 import javax.mail.Message;
 import javax.mail.MessagingException;
+import javax.mail.Store;
 import javax.mail.event.MessageCountAdapter;
 import javax.mail.event.MessageCountEvent;
 import javax.mail.event.MessageCountListener;
@@ -29,6 +30,7 @@ import javax.mail.search.FlagTerm;
 import javax.mail.search.NotTerm;
 import javax.mail.search.SearchTerm;
 
+import org.springframework.scheduling.TaskScheduler;
 import org.springframework.util.Assert;
 
 import com.sun.mail.imap.IMAPFolder;
@@ -48,6 +50,8 @@ import com.sun.mail.imap.IMAPFolder;
 public class ImapMailReceiver extends AbstractMailReceiver {
 	private volatile boolean shouldMarkMessagesAsRead = true;;
 	private final MessageCountListener messageCountListener = new SimpleMessageCountListener();
+	
+	private volatile long connectionPingInterval = 10000;
 
 
 	public ImapMailReceiver() {
@@ -179,6 +183,22 @@ public class ImapMailReceiver extends AbstractMailReceiver {
 		if (this.shouldMarkMessagesAsRead){
 			this.folderOpenMode = Folder.READ_WRITE;
 		}
+		this.initialized = true;
+		TaskScheduler scheduler = this.getTaskScheduler();
+		if (scheduler != null){
+			scheduler.scheduleAtFixedRate(new Runnable() {	
+				public void run() {
+					try {
+						Store store = getStore();
+						if (initialized && store != null){
+							store.isConnected();
+						}		
+					} 
+					catch (Throwable ignore) {
+					}
+				}
+			}, connectionPingInterval);
+		}
 	}
 	/**
 	 * 

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

@@ -1,8 +1,8 @@
-log4j.rootCategory=DEBUG, stdout
+log4j.rootCategory=WARN, stdout
 
 log4j.appender.stdout=org.apache.log4j.ConsoleAppender
 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
 log4j.appender.stdout.layout.ConversionPattern=%c{1}: %m%n
 
 log4j.category.org.springframework.integration=WARN
-log4j.category.org.springframework.integration.file=WARN
+log4j.category.org.springframework.integration.mail=WARN