Setting tomcat max file size and added error redirect on too large file

frontend/src/main/java/de/thm/spring/controller/ApplicationController.java

@@ -26,8 +26,12 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.multipart.MultipartException;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
 
 import javax.servlet.RequestDispatcher;
 import javax.servlet.http.HttpServletRequest;
@@ -112,6 +116,16 @@ public class ApplicationController implements ErrorController {
         return "error";
     }
 
+    @ControllerAdvice
+    public class FileErrorController extends ResponseEntityExceptionHandler {
+
+        @ExceptionHandler(MultipartException.class)
+        String handleFileException(HttpServletRequest request, Throwable ex, Model model) {
+            model.addAttribute("errorMessage", "The file you tried to upload is too large. Please upload only files with a max. file size of 20 MB.");
+            return "error";
+        }
+    }
+
     @RequestMapping("/faq")
     public String faq(){
 

frontend/src/main/resources/application.properties

@@ -5,5 +5,6 @@ logging.level.org.hibernate=INFO
 spring.mvc.favicon.enabled = false
 spring.servlet.multipart.max-file-size=20MB
 spring.servlet.multipart.max-request-size=20MB
+server.tomcat.max-swallow-size=20971520
 
 #management.security.enabled=false
\ No newline at end of file