Convert File usages to use FileLike or the comparable class

Author: Sigmonia

flow/src/org/labkey/flow/controllers/FlowController.java

@@ -41,6 +41,7 @@
 import org.labkey.api.security.permissions.ReadPermission;
 import org.labkey.api.settings.AdminConsole;
 import org.labkey.api.settings.AdminConsole.SettingsLinkType;
+import org.labkey.api.util.FileUtil;
 import org.labkey.api.util.JobRunner;
 import org.labkey.api.util.TestContext;
 import org.labkey.api.view.ActionURL;
@@ -64,11 +65,12 @@
 import org.labkey.flow.query.FlowSchema;
 import org.labkey.flow.webparts.FlowFolderType;
 import org.labkey.flow.webparts.OverviewWebPart;
+import org.labkey.vfs.FileLike;
+import org.labkey.vfs.FileSystemLike;
 import org.springframework.validation.BindException;
 import org.springframework.validation.Errors;
 import org.springframework.web.servlet.ModelAndView;
 
-import java.io.File;
 import java.net.URI;
 
 @Marshal(Marshaller.Jackson)
@@ -312,7 +314,9 @@ public boolean handlePost(FlowAdminForm form, BindException errors)
         {
             if (form.getWorkingDirectory() != null)
             {
-                File dir = new File(form.getWorkingDirectory());
+                FileLike dir = new FileSystemLike.Builder(FileUtil.stringToPath(getContainer(), form.getWorkingDirectory()))
+                        .readonly().root();
+
                 if (!dir.exists())
                 {
                     errors.rejectValue("workingDirectory", ERROR_MSG, "Path does not exist: " + form.getWorkingDirectory());