diff --git a/fesod/src/main/java/org/apache/fesod/sheet/cache/selector/SimpleReadCacheSelector.java b/fesod/src/main/java/org/apache/fesod/sheet/cache/selector/SimpleReadCacheSelector.java
index 85a2e8dc4..ef1a7acd4 100644
--- a/fesod/src/main/java/org/apache/fesod/sheet/cache/selector/SimpleReadCacheSelector.java
+++ b/fesod/src/main/java/org/apache/fesod/sheet/cache/selector/SimpleReadCacheSelector.java
@@ -114,13 +114,9 @@ public ReadCache readCache(PackagePart sharedStringsTablePackagePart) {
 
         // In order to be compatible with the code
         // If the user set up `maxCacheActivateSize`, then continue using it
-        if (maxCacheActivateSize != null) {
-            return new Ehcache(maxCacheActivateSize, maxCacheActivateBatchCount);
-        } else {
-            if (maxCacheActivateBatchCount == null) {
-                maxCacheActivateBatchCount = DEFAULT_MAX_EHCACHE_ACTIVATE_BATCH_COUNT;
-            }
-            return new Ehcache(maxCacheActivateSize, maxCacheActivateBatchCount);
+        if (maxCacheActivateBatchCount == null) {
+            maxCacheActivateBatchCount = DEFAULT_MAX_EHCACHE_ACTIVATE_BATCH_COUNT;
         }
+        return new Ehcache(maxCacheActivateSize, maxCacheActivateBatchCount);
     }
 }
diff --git a/fesod/src/main/java/org/apache/fesod/sheet/metadata/format/DataFormatter.java b/fesod/src/main/java/org/apache/fesod/sheet/metadata/format/DataFormatter.java
index 8ab4bf1a0..ec37963dd 100644
--- a/fesod/src/main/java/org/apache/fesod/sheet/metadata/format/DataFormatter.java
+++ b/fesod/src/main/java/org/apache/fesod/sheet/metadata/format/DataFormatter.java
@@ -747,7 +747,6 @@ public static void setExcelStyleRoundingMode(DecimalFormat format, RoundingMode
     /**
      * Format class for Excel's SSN format. This class mimics Excel's built-in SSN formatting.
      */
-    @SuppressWarnings("serial")
     private static final class SSNFormat extends Format {
         private static final DecimalFormat df = createIntegerOnlyFormat("000000000");
 
@@ -777,7 +776,6 @@ public Object parseObject(String source, ParsePosition pos) {
     /**
      * Format class for Excel Zip + 4 format. This class mimics Excel's built-in formatting for Zip + 4.
      */
-    @SuppressWarnings("serial")
     private static final class ZipPlusFourFormat extends Format {
         private static final DecimalFormat df = createIntegerOnlyFormat("000000000");
 
@@ -807,7 +805,6 @@ public Object parseObject(String source, ParsePosition pos) {
     /**
      * Format class for Excel phone number format. This class mimics Excel's built-in phone number formatting.
      */
-    @SuppressWarnings("serial")
     private static final class PhoneFormat extends Format {
         private static final DecimalFormat df = createIntegerOnlyFormat("##########");
 
@@ -857,7 +854,7 @@ public Object parseObject(String source, ParsePosition pos) {
      * non-cachable wrapper around a
      * {@link CellFormatResult}
      */
-    private final class CellFormatResultWrapper extends Format {
+    private static final class CellFormatResultWrapper extends Format {
         private final CellFormatResult result;
 
         private CellFormatResultWrapper(CellFormatResult result) {