spring Jdbc自动获取主键。

spring 搭建底层框架，本来简单的save保存对象，可是需要返回主键，那么就用一下代码实现。

public Long createOrder(final Order order) throws Exception {

KeyHolder keyHolder = new GeneratedKeyHolder();

try {

jdbcTemplate.update(new PreparedStatementCreator() {

@Override

public PreparedStatement createPreparedStatement(

Connection connection) throws SQLException
{

//拼装插入数据库的sql

String sql = orderSql(order);

PreparedStatement ps = connection.prepareStatement(sql);

return ps;

}

},
keyHolder);

} catch (Exception e) {

e.printStackTrace();

return null;

}

return keyHolder.getKey().longValue();

}