Replace string concatenation w/ StringBuilder in loops

Author: simon04

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerDatabaseMetaData.java

@@ -521,17 +521,16 @@ public java.sql.ResultSet getTables(String catalog, String schema, String table,
         arguments[1] = schema;
         arguments[2] = catalog;
 
-        String tableTypes = null;
         if (types != null) {
-            tableTypes = "'";
+            final StringBuilder tableTypes = new StringBuilder("'");
             for (int i = 0; i < types.length; i++) {
                 if (i > 0)
-                    tableTypes += ",";
-                tableTypes += "''" + types[i] + "''";
+                    tableTypes.append(",");
+                tableTypes.append("''").append(types[i]).append("''");
             }
-            tableTypes += "'";
+            tableTypes.append("'");
+            arguments[3] = tableTypes.toString();
         }
-        arguments[3] = tableTypes;
         return getResultSetWithProvidedColumnNames(catalog, CallableHandles.SP_TABLES, arguments, getTablesColumnNames);
     }
 

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerStatement.java

@@ -1012,29 +1012,28 @@ static String replaceParameterWithString(String str, char marker, String replace
      */
     static String replaceMarkerWithNull(String sql) {
         if (!sql.contains("'")) {
-            String retStr = replaceParameterWithString(sql, '?', "null");
-            return retStr;
+            return replaceParameterWithString(sql, '?', "null");
         } else {
             StringTokenizer st = new StringTokenizer(sql, "'", true);
             boolean beforeColon = true;
-            String retSql = "";
+            final StringBuilder retSql = new StringBuilder();
             while (st.hasMoreTokens()) {
                 String str = st.nextToken();
                 if (str.equals("'")) {
-                    retSql += "'";
+                    retSql.append("'");
                     beforeColon = !beforeColon;
                     continue;
                 }
                 if (beforeColon) {
                     String repStr = replaceParameterWithString(str, '?', "null");
-                    retSql += repStr;
+                    retSql.append(repStr);
                     continue;
                 } else {
-                    retSql += str;
+                    retSql.append(str);
                     continue;
                 }
             }
-            return retSql;
+            return retSql.toString();
         }
     }