以下java函数未将数据插入数据库，

Question

我创建了此函数以获取哈希映射字符串，字符串值和table_name 如何在控制器中调用此函数以将其插入数据库。

 public void insert_record(HashMap<String, String> dataMap, String tableName) throws SQLException {

        StringBuilder sql = new StringBuilder("INSERT INTO ").append(tableName).append(" (");
        StringBuilder placeholders = new StringBuilder();

        for (Iterator<String> iter = dataMap.keySet().iterator(); iter.hasNext();) {
            sql.append(iter.next());
            placeholders.append("?");

            if (iter.hasNext()) {
                sql.append(",");
                placeholders.append(",");
            }
        }

        sql.append(") VALUES (").append(placeholders).append(")");

        PreparedStatement PreparedStatement = conn.prepareStatement(sql.toString());
        //System.out.println(PreparedStatement);
        int i = 0;

        for (String value : dataMap.values()) {
            PreparedStatement.setObject(i++, value);
        }


        int affectedRows = PreparedStatement.executeUpdate();

    }