Do not allocate byte array in case there is no data

1 files changed, 5 insertions, 4 deletions

diff --git a/src/main/java/com/it_jaros/jns/scan/engine/ScanPortTask.java b/src/main/java/com/it_jaros/jns/scan/engine/ScanPortTask.java
index e9244c2..dc5851e 100644
--- a/src/main/java/com/it_jaros/jns/scan/engine/ScanPortTask.java
+++ b/src/main/java/com/it_jaros/jns/scan/engine/ScanPortTask.java
@@ -11,6 +11,7 @@ import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.channels.SocketChannel;
+import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
@@ -64,7 +65,7 @@ public class ScanPortTask implements Callable<PortResult> {
             PortState state = getPortState(socketChannel);
             result.setState(state);
             if (PortState.OPEN.equals(state) && bannerRecognition) {
-                result.setBanner(getBanner(socketChannel));
+                getBanner(socketChannel).ifPresent(result::setBanner);
             }
         } catch (ConnectException ignored) {
             result.setState(PortState.CLOSED);
@@ -101,14 +102,14 @@ public class ScanPortTask implements Callable<PortResult> {
         return PortState.FILTERED;
     }
 
-    private byte[] getBanner(SocketChannel socketChannel) {
+    private Optional<byte[]> getBanner(SocketChannel socketChannel) {
         try {
-            return tryReadFrom(socketChannel);
+            return Optional.of(tryReadFrom(socketChannel));
         } catch (IOException ignore) {
             // ignore
         }
 
-        return new byte[0];
+        return Optional.empty();
     }
 
     private byte[] tryReadFrom(SocketChannel socketChannel) throws IOException {