set exceptions on join group

added emoji to error.html <- wichtig

                                                          Co-authored-by: AndiBuls <andreas.buls@uni-duesseldorf.de>

src/main/java/mops/gruppen2/controller/Gruppen2Controller.java

@@ -6,10 +6,7 @@ import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.Role;
 import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.Visibility;
-import mops.gruppen2.domain.exception.EventException;
-import mops.gruppen2.domain.exception.GroupNotFoundException;
-import mops.gruppen2.domain.exception.WrongFileException;
-import mops.gruppen2.domain.exception.NoAdminAfterActionException;
+import mops.gruppen2.domain.exception.*;
 import mops.gruppen2.security.Account;
 import mops.gruppen2.service.ControllerService;
 import mops.gruppen2.service.CsvService;
@@ -34,8 +31,6 @@ import javax.annotation.security.RolesAllowed;
 import javax.servlet.http.HttpServletRequest;
 import java.io.CharConversionException;
 import java.io.IOException;
-import java.net.InetAddress;
-import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Logger;
@@ -249,9 +244,11 @@ public class Gruppen2Controller {
         User user = new User(account.getName(), account.getGivenname(), account.getFamilyname(), account.getEmail());
         Group group = userService.getGroupById(groupId);
         if (group.getMembers().contains(user)) {
-            return "error"; //hier soll eigentlich auf die bereits beigetretene Gruppe weitergeleitet werden
+            throw new UserAlreadyExistsException("Du bist bereits in dieser Gruppe.");
+        }
+        if (group.getUserMaximum() < group.getMembers().size()) {
+            throw new GroupFullException("Du kannst der Gruppe daher leider nicht beitreten.");
         }
-        if (group.getUserMaximum() < group.getMembers().size()) return "error";
         controllerService.addUser(account, groupId);
         return "redirect:/gruppen2/";
     }

src/main/java/mops/gruppen2/controller/MopsController.java

@@ -1,5 +1,7 @@
 package mops.gruppen2.controller;
 
+import mops.gruppen2.domain.exception.EventException;
+import mops.gruppen2.domain.exception.PageNotFoundException;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.GetMapping;
 
@@ -20,7 +22,7 @@ public class MopsController {
     }
 
     @GetMapping("*")
-    public String defaultLink() {
-        return "error";
+    public String defaultLink() throws EventException {
+        throw new PageNotFoundException("\uD83D\uDE41");
     }
 }

src/main/java/mops/gruppen2/domain/exception/GroupFullException.java

@@ -5,7 +5,7 @@ import org.springframework.http.HttpStatus;
 public class GroupFullException extends EventException {
 
 	public GroupFullException(String info) {
-		super(HttpStatus.INTERNAL_SERVER_ERROR, "Der User existiert bereits.", info);
+		super(HttpStatus.INTERNAL_SERVER_ERROR, "Die Gruppe hat die maximale Midgliederanzahl bereits erreicht!", info);
 	}
 }
 

src/main/java/mops/gruppen2/domain/exception/PageNotFoundException.java

@@ -0,0 +1,9 @@
+package mops.gruppen2.domain.exception;
+
+import org.springframework.http.HttpStatus;
+
+public class PageNotFoundException extends EventException {
+    public PageNotFoundException(String info) {
+        super(HttpStatus.NOT_FOUND, "Die Seite wurde nicht gefunden!", info);
+    }
+}

src/main/resources/templates/error.html

@@ -27,9 +27,8 @@
             </div>
         </div>
 
-        <button style="color: #52a1eb">
-            <a  style="color: white" class="btn btn-primary btn-lg" href="#" onclick="window.history.back(-1);return false;" role="button">Zurück</a>
-        </button>
+        <a style="background-color: #52a1eb; color: white" class="btn btn-lg" href="#"
+           onclick="window.history.back(-1);return false;" role="button">Zurück</a>
     </div>
 </div>
 </body>