diff --git a/src/main/java/org/codelibs/fess/helper/SambaHelper.java b/src/main/java/org/codelibs/fess/helper/SambaHelper.java
index 48f487f76..cf5bdd431 100644
--- a/src/main/java/org/codelibs/fess/helper/SambaHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/SambaHelper.java
@@ -58,7 +58,7 @@ public class SambaHelper {
         if (logger.isDebugEnabled()) {
             try {
                 logger.debug("Processing SID: {} {} {}", type, sid, sid.toDisplayString());
-            } catch (Exception e) {
+            } catch (final Exception e) {
                 // ignore
             }
         }
diff --git a/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java b/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
index c37008796..03f8b6b0f 100644
--- a/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
+++ b/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
@@ -216,7 +216,7 @@ public class ThumbnailManager {
         }).filter(f -> f != null).forEach(f -> {
             try {
                 f.get();
-            } catch (Exception e) {
+            } catch (final Exception e) {
                 logger.warn("Failed to process a thumbnail generation.", e);
             }
         });
diff --git a/src/main/java/org/codelibs/fess/util/EsUtil.java b/src/main/java/org/codelibs/fess/util/EsUtil.java
index ec8aaf7da..d4c6cbc1f 100644
--- a/src/main/java/org/codelibs/fess/util/EsUtil.java
+++ b/src/main/java/org/codelibs/fess/util/EsUtil.java
@@ -37,7 +37,7 @@ public final class EsUtil {
         try (final XContentBuilder builder = xContent.toXContent(XContentFactory.contentBuilder(xContentType), ToXContent.EMPTY_PARAMS)) {
             builder.flush();
             return builder.getOutputStream();
-        } catch (IOException e) {
+        } catch (final IOException e) {
             if (logger.isDebugEnabled()) {
                 logger.debug("Failed to print the output.", e);
             }