Don't pop up notifications when server is under maintenance.

app/src/main/java/com/etesync/syncadapter/journalmanager/Exceptions.kt

@@ -18,7 +18,7 @@ class Exceptions {
 
     class BadGatewayException(response: Response, message: String) : HttpException(response, message)
 
-    class ServiceUnavailableException : HttpException {
+    class ServiceUnavailableException : IgnorableHttpException {
         var retryAfter: Long = 0
 
         constructor(message: String) : super(message) {
@@ -32,6 +32,10 @@ class Exceptions {
 
     class IntegrityException(message: String) : GeneralSecurityException(message)
 
+    open class IgnorableHttpException : HttpException {
+        constructor(message: String) : super(message)
+        constructor(response: Response, message: String) : super(response, message)
+    }
 
     open class GenericCryptoException(message: String) : Exception(message)
 

app/src/main/java/com/etesync/syncadapter/syncadapter/AddressBooksSyncAdapterService.kt

@@ -72,6 +72,8 @@ class AddressBooksSyncAdapterService : SyncAdapterService() {
             } catch (e: Exceptions.ServiceUnavailableException) {
                 syncResult.stats.numIoExceptions++
                 syncResult.delayUntil = if (e.retryAfter > 0) e.retryAfter else Constants.DEFAULT_RETRY_DELAY
+            } catch (e: Exceptions.IgnorableHttpException) {
+                // Ignore
             } catch (e: Exception) {
                 if (e is ContactsStorageException || e is SQLiteException) {
                     App.log.log(Level.SEVERE, "Couldn't prepare local address books", e)

app/src/main/java/com/etesync/syncadapter/syncadapter/CalendarsSyncAdapterService.kt

@@ -60,6 +60,8 @@ class CalendarsSyncAdapterService : SyncAdapterService() {
             } catch (e: Exceptions.ServiceUnavailableException) {
                 syncResult.stats.numIoExceptions++
                 syncResult.delayUntil = if (e.retryAfter > 0) e.retryAfter else Constants.DEFAULT_RETRY_DELAY
+            } catch (e: Exceptions.IgnorableHttpException) {
+                // Ignore
             } catch (e: Exception) {
                 if (e is CalendarStorageException || e is SQLiteException) {
                     App.log.log(Level.SEVERE, "Couldn't prepare local calendars", e)

app/src/main/java/com/etesync/syncadapter/syncadapter/SyncManager.kt

@@ -187,6 +187,8 @@ constructor(protected val context: Context, protected val account: Account, prot
         } catch (e: InterruptedException) {
             // Restart sync if interrupted
             syncResult.fullSyncRequested = true
+        } catch (e: Exceptions.IgnorableHttpException) {
+            // Ignore
         } catch (e: Exception) {
             if (e is Exceptions.UnauthorizedException) {
                 syncResult.stats.numAuthExceptions++

app/src/main/java/com/etesync/syncadapter/syncadapter/TasksSyncAdapterService.kt

@@ -77,6 +77,8 @@ class TasksSyncAdapterService: SyncAdapterService() {
             } catch (e: Exceptions.ServiceUnavailableException) {
                 syncResult.stats.numIoExceptions++
                 syncResult.delayUntil = if (e.retryAfter > 0) e.retryAfter else Constants.DEFAULT_RETRY_DELAY
+            } catch (e: Exceptions.IgnorableHttpException) {
+                // Ignore
             } catch (e: Exception) {
                 if (e is SQLiteException) {
                     App.log.log(Level.SEVERE, "Couldn't prepare local task list", e)