best epoch 파일 선택 수정

src/main/java/com/kamco/cd/training/train/service/DockerTrainService.java

@@ -9,6 +9,7 @@ import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -414,12 +415,10 @@ public class DockerTrainService {
     if (uuid == null || uuid.isBlank()) throw new IllegalArgumentException("uuid is required");
     if (epoch == null || epoch <= 0) throw new IllegalArgumentException("epoch must be > 0");
 
-    String modelFile =
+    Path epochPath = Paths.get(responseDir, req.getOutputFolder());
-        String.valueOf(findCheckpoint(Path.of(responseDir + req.getOutputFolder()), epoch));
 
-    if (modelFile == null || modelFile.isBlank()) {
+    Path checkpoint = findCheckpoint(epochPath, epoch);
-      throw new IllegalArgumentException("best model file is required");
+    String modelFile = checkpoint.toString();
-    }
 
     List<String> c = new ArrayList<>();
 
@@ -469,7 +468,6 @@ public class DockerTrainService {
       return normalPath;
     }
 
-    // 둘 다 없으면 null 또는 예외
+    throw new IllegalStateException("Checkpoint 파일이 없습니다. epoch=" + epoch);
-    return null;
   }
 }