fix #1521

client-adapter/rdb/src/main/java/com/alibaba/otter/canal/client/adapter/rdb/support/BatchExecutor.java

@@ -52,16 +52,17 @@ public class BatchExecutor implements Closeable {
     }
 
     public void execute(String sql, List<Map<String, ?>> values) throws SQLException {
-        PreparedStatement pstmt = getConn().prepareStatement(sql);
-        int len = values.size();
-        for (int i = 0; i < len; i++) {
-            int type = (Integer) values.get(i).get("type");
-            Object value = values.get(i).get("value");
-            SyncUtil.setPStmt(type, pstmt, value, i + 1);
-        }
+        try (PreparedStatement pstmt = getConn().prepareStatement(sql)) {
+            int len = values.size();
+            for (int i = 0; i < len; i++) {
+                int type = (Integer) values.get(i).get("type");
+                Object value = values.get(i).get("value");
+                SyncUtil.setPStmt(type, pstmt, value, i + 1);
+            }
 
-        pstmt.execute();
-        idx.incrementAndGet();
+            pstmt.execute();
+            idx.incrementAndGet();
+        }
     }
 
     public void commit() throws SQLException {