Handle NPE (#2906)

* Handle NPE

* Add Unit Test

src/main/java/io/lettuce/core/codec/ByteArrayCodec.java

@@ -90,9 +90,11 @@ public ByteBuffer encodeValue(byte[] value) {
     }
 
     private static byte[] getBytes(ByteBuffer buffer) {
+        if (buffer == null) {
+            return EMPTY;
+        }
 
         int remaining = buffer.remaining();
-
         if (remaining == 0) {
             return EMPTY;
         }

src/test/java/io/lettuce/core/codec/ByteArrayCodecUnitTests.java

@@ -0,0 +1,35 @@
+package io.lettuce.core.codec;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.ByteBuffer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ByteArrayCodecUnitTests {
+
+    @Test
+    void testDecodeValue_withNonEmptyByteBuffer() {
+        final ByteArrayCodec byteArrayCodec = ByteArrayCodec.INSTANCE;
+        final byte[] expectedBytes = { 1, 2, 3, 4, 5 };
+        final ByteBuffer buffer = ByteBuffer.wrap(expectedBytes);
+        final byte[] result = byteArrayCodec.decodeValue(buffer);
+        assertThat(result).isEqualTo(expectedBytes);
+    }
+
+    @Test
+    void testDecodeValue_withEmptyByteBuffer() {
+        final ByteArrayCodec byteArrayCodec = ByteArrayCodec.INSTANCE;
+        final ByteBuffer buffer = ByteBuffer.allocate(0);
+        final byte[] result = byteArrayCodec.decodeValue(buffer);
+        assertThat(result).isEmpty();
+    }
+
+    @Test
+    void testDecodeValue_withNullByteBuffer() {
+        final ByteArrayCodec byteArrayCodec = ByteArrayCodec.INSTANCE;
+        final byte[] result = byteArrayCodec.decodeValue(null);
+        assertThat(result).isEmpty();
+    }
+
+}