fix: avoid NPE when transaction is not found (#313)

Co-authored-by: Mateusz Czeladka <[email protected]>

Author: matiwinnetou

api/src/main/java/org/cardanofoundation/rosetta/api/search/controller/SearchApiImpl.java

@@ -35,12 +35,11 @@ public class SearchApiImpl implements SearchApi {
   @Override
   public ResponseEntity<SearchTransactionsResponse> searchTransactions(
       SearchTransactionsRequest searchTransactionsRequest) {
-    if(offlineMode) {
+    if (offlineMode) {
       throw ExceptionFactory.notSupportedInOfflineMode();
     }
     networkService.verifyNetworkRequest(searchTransactionsRequest.getNetworkIdentifier());
 
-
     Long pageSize = Optional.ofNullable(searchTransactionsRequest.getLimit()).orElse(PAGE_SIZE);
     pageSize = pageSize > PAGE_SIZE ? PAGE_SIZE : pageSize;
     Long offset = Optional.ofNullable(searchTransactionsRequest.getOffset()).orElse(0L);
@@ -51,6 +50,6 @@ public ResponseEntity<SearchTransactionsResponse> searchTransactions(
 
     return ResponseEntity.ok(searchMapper.mapToSearchTransactionsResponse(
         blockTransactions, nextOffset));
-
   }
+
 }

api/src/main/java/org/cardanofoundation/rosetta/common/exception/ApiException.java

@@ -12,7 +12,8 @@ public class ApiException extends RuntimeException {
   private final Error error;
 
   public ApiException(Error error) {
-    super();
+    super(error.getMessage() == null ? "?" : error.getMessage());
     this.error = error;
   }
+
 }