corrections

WEB-INF/src/controleurs/Discover.java

@@ -47,10 +47,13 @@ public class Discover extends HttpServlet {
                         } catch (SQLException e) {
                             throw new RuntimeException(e);
                         }
+                        User sender = userDao.getUserById(message.getSenderId());
+                        String senderName = sender.getUserName();
+                        
                         out.println("<div class=\"message\">");
                         out.println("<h3 class=\"msgThread\">" + msgThread.getThreadName() + "</h3>");
                         out.println("<p class=\"msgContent\">" + message.getContent() + "</p>");
-                        out.println("<p class=\"sender\">by " + userDao.getUserById(message.getSenderId()).getUserName() + "</p>");
+                        out.println("<p class=\"sender\">by " + senderName + "</p>");
 
                         out.println("<form class=\"followThread\" action=\"http://localhost:8080/s4a021-web-backend/FollowThread\" method=\"post\">");
                         out.println("<input name=\"threadid\" type=\"hidden\" value=\"" + msgThread.getId() +"\">");

WEB-INF/src/controleurs/Feed.java

@@ -81,7 +81,7 @@ public class Feed extends HttpServlet {
             }
 
             out.println("<div class=\"discover\">");
-            out.println("<a href=\"\">Discover new threads</a>");
+            out.println("<a href=\"http://localhost:8080/s4a021-web-backend/Discover\">Discover new threads</a>");
             out.println("<a href=\"http://localhost:8080/s4a021-web-backend/NewThread\">Create a new thread</a>");
             out.println("</div>");
 

WEB-INF/src/controleurs/Following.java

@@ -62,7 +62,7 @@ public class Following extends HttpServlet {
 
                     out.println("<div class=\"thread\">");
                     out.println("<h3 class=\"threadname\">Thread name: " + t.getThreadName() + "</h3>");
-                    out.println("<h4 class=\"followDate\">Following since: " + followDate + "</h4>");
+                    out.println("<p class=\"followDate\">Following since: " + followDate + "</p>");
                     out.println("</div>");
                 }
             }

WEB-INF/src/controleurs/NewThread.java

@@ -63,7 +63,7 @@ public class NewThread extends HttpServlet {
             out.println("<h3>Create a new thread</h3>");
             out.println("<form action=\"http://localhost:8080/s4a021-web-backend/NewThread\" method=\"post\">");
             out.println("<input name=\"threadname\" type=\"text\" placeholder=\"Name of new thread\">");
-            out.println("<textarea name=\"first_message\" type=\"text\" rows=\"2\" cols=\"30\" placeholder=\"Post the first message of your new thread!\">");
+            out.println("<textarea name=\"first_message\" type=\"text\" rows=\"2\" cols=\"30\" placeholder=\"Post the first message of your new thread!\"></textarea>");
             out.println("<button type=\"submit\">Create</button>");
             out.println("</form>");
 

WEB-INF/src/dao/UserDAO.java

@@ -100,7 +100,7 @@ public class UserDAO {
         User user = new User(0,null,null);
 
         try{
-            PreparedStatement stmt = this.con.prepareStatement("SELECT * FROM userAccount WHERE id=?");
+            PreparedStatement stmt = this.con.prepareStatement("SELECT * FROM userAccount WHERE userid=?");
             stmt.setInt(1, id);
             ResultSet rs = stmt.executeQuery();