fixed graph not-found error handling

Author: rashtao

core/src/main/java/com/arangodb/internal/ArangoGraphAsyncImpl.java

@@ -32,6 +32,8 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 
+import static com.arangodb.internal.ArangoErrors.ERROR_GRAPH_NOT_FOUND;
+
 public class ArangoGraphAsyncImpl extends InternalArangoGraph implements ArangoGraphAsync {
 
     private final ArangoDatabaseAsync db;
@@ -54,7 +56,7 @@ public CompletableFuture<Boolean> exists() {
                     Throwable e = err instanceof CompletionException ? err.getCause() : err;
                     if (e instanceof ArangoDBException) {
                         ArangoDBException aEx = (ArangoDBException) e;
-                        if (ArangoErrors.ERROR_GRAPH_NOT_FOUND.equals(aEx.getErrorNum())) {
+                        if (ArangoErrors.matches(aEx, 404, ERROR_GRAPH_NOT_FOUND)) {
                             return false;
                         }
                     }

core/src/main/java/com/arangodb/internal/ArangoGraphImpl.java

@@ -29,6 +29,9 @@
 
 import java.util.Collection;
 
+import static com.arangodb.internal.ArangoErrors.ERROR_GRAPH_NOT_FOUND;
+import static com.arangodb.internal.ArangoErrors.matches;
+
 /**
  * @author Mark Vollmary
  */
@@ -52,7 +55,7 @@ public boolean exists() {
             getInfo();
             return true;
         } catch (final ArangoDBException e) {
-            if (ArangoErrors.ERROR_GRAPH_NOT_FOUND.equals(e.getErrorNum())) {
+            if (matches(e, 404, ERROR_GRAPH_NOT_FOUND)) {
                 return false;
             }
             throw e;