public User queryById() {
//new RowMapper 对查询结直接进行处理,返回list
List<User> query = jdbcTemplate.query("select * from user where id = ?", new RowMapper<User>() {
public User mapRow(ResultSet resultSet, int i) throws SQLException {
String name = resultSet.getString("name");
int id = resultSet.getInt("id");
return new User(id,name);
}
},1);
// 结果集不为空,返回元素
return query.size()==0?null:query.get(0);
}