jdbc通用表查询

@Override
    public <T> List<T> showUser(Connection connection, Class<T> tClass, String tableName) {
        List<T> t = null;
        QueryRunner queryRunner = new QueryRunner();
        String sql = "select * from "+tableName;
        System.out.println(sql);
        BeanListHandler<T> beanListHandler;
        beanListHandler = new BeanListHandler<T>(tClass);
        try {
            t = queryRunner.query(connection, sql, beanListHandler);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        System.out.println(t.toString());
        return t;
    }