diff --git a/src/main/java/xyz/zhouxy/jdbc/JdbcOperationSupport.java b/src/main/java/xyz/zhouxy/jdbc/JdbcOperationSupport.java
index a2ccefc..a64624e 100644
--- a/src/main/java/xyz/zhouxy/jdbc/JdbcOperationSupport.java
+++ b/src/main/java/xyz/zhouxy/jdbc/JdbcOperationSupport.java
@@ -225,19 +225,19 @@ class JdbcOperationSupport {
         }
 
         final int paramsSize = params.size();
-        int batchCount = (paramsSize + batchSize - 1) / batchSize;
+        final int batchCount = (paramsSize + batchSize - 1) / batchSize;
 
         final BatchUpdateResult result = new BatchUpdateResult(paramsSize, batchCount, batchSize);
 
         try (PreparedStatement stmt = conn.prepareStatement(sql)) {
-            int i = 0;
+            int itemIndex = 0;
             int batchIndex = 0;
             for (Object[] ps : params) {
-                i++;
+                itemIndex++;
                 fillStatement(stmt, ps);
                 stmt.addBatch();
-                final int indexInBatch = i % batchSize;
-                if (indexInBatch == 0 || i >= paramsSize) {
+                final int indexInBatch = itemIndex % batchSize;
+                if (indexInBatch == 0 || itemIndex >= paramsSize) {
                     try {
                         int[] updateCounts = stmt.executeBatch();
                         result.recordSuccessBatch(batchIndex, updateCounts);
@@ -248,7 +248,7 @@ class JdbcOperationSupport {
                             updateCounts = ((BatchUpdateException) e).getUpdateCounts();
                         }
                         else {
-                            int n = (i >= paramsSize && indexInBatch != 0) ? indexInBatch : batchSize;
+                            int n = (itemIndex >= paramsSize && indexInBatch != 0) ? indexInBatch : batchSize;
                             updateCounts = new int[n];
                             Arrays.fill(updateCounts, UNKNOWN_COUNT);
                         }
diff --git a/src/main/java/xyz/zhouxy/jdbc/SimpleJdbcTemplate.java b/src/main/java/xyz/zhouxy/jdbc/SimpleJdbcTemplate.java
index 6ec96de..d422dd3 100644
--- a/src/main/java/xyz/zhouxy/jdbc/SimpleJdbcTemplate.java
+++ b/src/main/java/xyz/zhouxy/jdbc/SimpleJdbcTemplate.java
@@ -204,7 +204,7 @@ public class SimpleJdbcTemplate implements JdbcOperations {
             final boolean autoCommit = conn.getAutoCommit();
             try {
                 conn.setAutoCommit(false);
-                operations.accept(new JdbcExecutor(conn));
+                operations.accept(new TransactionJdbcExecutor(conn));
                 conn.commit();
             }
             catch (Exception e) {
@@ -240,7 +240,7 @@ public class SimpleJdbcTemplate implements JdbcOperations {
             final boolean autoCommit = conn.getAutoCommit();
             try {
                 conn.setAutoCommit(false);
-                if (operations.test(new JdbcExecutor(conn))) {
+                if (operations.test(new TransactionJdbcExecutor(conn))) {
                     conn.commit();
                 }
                 else {
@@ -264,11 +264,11 @@ public class SimpleJdbcTemplate implements JdbcOperations {
 
     // #endregion
 
-    private static final class JdbcExecutor implements JdbcOperations {
+    private static final class TransactionJdbcExecutor implements JdbcOperations {
 
         private final Connection conn;
 
-        private JdbcExecutor(Connection conn) {
+        private TransactionJdbcExecutor(Connection conn) {
             this.conn = conn;
         }