Can't Save a Database to a new File (JabRef#3022)

* Updated maven repo

* #1 fixed, in case the old file is not there we just save the new file

* #1 adjustments

* #1 adjustments

* fixes for checkstyle and improvements on file path verification

gradle/wrapper/gradle-wrapper.properties

@@ -1,4 +1,4 @@
-#Sun Jul 09 12:08:20 CEST 2017
+#Tue Jul 18 01:58:04 BRT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME

src/main/java/org/jabref/gui/exporter/SaveDatabaseAction.java

@@ -316,8 +316,7 @@ public void saveAs() throws Exception {
      */
     public void saveAs(File file) throws Exception {
         BibDatabaseContext context = panel.getBibDatabaseContext();
-        Path oldFile = context.getDatabasePath().get();
-
+
         if (context.getLocation() == DatabaseLocation.SHARED) {
             // Save all properties dependent on the ID. This makes it possible to restore them.
             DBMSConnectionProperties properties = context.getDBMSSynchronizer().getDBProcessor()
@@ -336,12 +335,18 @@ public void saveAs(File file) throws Exception {
             return;
         }
 
-        //closing AutosaveManager and BackupManager for original library 
-        context.setDatabaseFile(oldFile.toFile());
-        AutosaveManager.shutdown(context);
-        BackupManager.shutdown(context);
+        Optional<Path> databasePath = context.getDatabasePath();
+        if (databasePath.isPresent()) {
+            final Path oldFile = databasePath.get();
+            context.setDatabaseFile(oldFile.toFile());
+            //closing AutosaveManager and BackupManager for original library
+            AutosaveManager.shutdown(context);
+            BackupManager.shutdown(context);
+        } else {
+            LOGGER.info("Old file not found, just creating a new file");
+        }
         context.setDatabaseFile(file);
-        
+
         // Register so we get notifications about outside changes to the file.
         try {
             panel.setFileMonitorHandle(Globals.getFileUpdateMonitor().addUpdateListener(panel,