small code refactor

Author: ntbeastboy

client/src/main/java/com/auction/service/rest/RestBidService.java

@@ -37,6 +37,9 @@ public Bid placeBid(User user, String itemId, double amount) {
     Map<String, Object> body = new LinkedHashMap<>();
     body.put("itemId", itemId);
     body.put("bidAmount", amount);
+    if(user.isBanned()) {
+      throw new InvalidBidException("Your account is banned. You cannot place bids.");
+    }
     try {
       String response = http.post("/bids", http.getGson().toJson(body));
       Map<String, Object> map = http.getGson().fromJson(response, MAP);
@@ -68,6 +71,9 @@ public AutoBid setAutoBid(User user, String itemId, double maxBid, double increm
     body.put("itemId", itemId);
     body.put("maxBid", maxBid);
     body.put("increment", increment);
+    if(user.isBanned()) {
+      throw new InvalidBidException("Your account is banned. You cannot set auto-bids.");
+    }
     try {
       String response = http.post("/auto-bids", http.getGson().toJson(body));
       Map<String, Object> map = http.getGson().fromJson(response, MAP);
@@ -92,6 +98,9 @@ public Optional<AutoBid> getAutoBid(User user, String itemId) {
 
   @Override
   public void cancelAutoBid(User user, String itemId) {
+    if(user.isBanned()) {
+      throw new InvalidBidException("Your account is banned. You cannot cancel auto-bids.");
+    }
     try {
       String encodedItemId =
           java.net.URLEncoder.encode(itemId, java.nio.charset.StandardCharsets.UTF_8);