databank verbinding in app.ts uitgezet, dummy json bodies toegevoegd in verschillende routes

backend/src/routes/class.ts

@@ -3,7 +3,15 @@ const router = express.Router();
 
 // information about an class with id 'id'
 router.get('/:id', (req, res) => {
-    res.send('class');
+    res.json({
+        id: req.params.id,
+        displayName: 'Klas 4B',
+        teachers: [ '0' ],
+        students: [ '0' ],
+        assignments: [ '0' ],
+        joinRequests: [ '0' ],
+        invitations: [ '0' ],
+    });
 })
 
 export default router