Spring 可代码简化操作类

         SimpleJdbcTemplate类是JdbcTemplate类的一个包装器，它利用了java5的一些语句特性以实现代码的简单化。

                        public User findUser(long id){

                                  String sql="select id,username,password,email from user where id=?";
                                  ParameterizedRowMapper<User> mapper= new ParameterizedRowMapper<User>(){
                                            public Object mapRow(ResultSet rs,int rowNum)throws SQLException{
                                                       User user = new User();
                                                        user.setId(rs.getLong("id"));
                                                        user.setUsername(rs.getString("username"));
                                                        user.setPassword(rs.getString("password"));
                                                        user.setEmail(rs.getString("email"));
                                                        return user;
        }
  };
                                  SimpleJdbcTemplate simplejdbc = new JdbcTemplate(dataSource);
                                   return (User)simplejdbc.queryForObject(sql,mapper,id});
}

}

           这里使用了参数化的类型ParamerizedRowMapper<User>,使用了泛型的样式，这样在执行查询时就不需要进行类型转化，这也是符合了Java5的泛型思想。