从字符串中标记/提取信息的最佳方法
我正在尝试将收到的日期时间转换为特定格式以插入到 MySQL 数据库中。该程序是用 C++ 编写的，下面的解决方案可以工作，但我觉得它的效率非常低。
输入为：Mon Nov 08 17:41:23 +0000 2010
所需的输出格式为：YYYY-MM-DD HH:MM:SS
因此，对于这个示例，输出将是： 2010-11-08 17:41:23
我已经包含了代码的相关部分。
//class variable
std::map<std::string, std::string> monthMap;
void processor::initializeMonthMap(){
monthMap["Jan"] = "01";
monthMap["Feb"] = "02";
monthMap["Mar"] = "03";
monthMap["Apr"] = "04";
monthMap["May"] = "05";
monthMap["Jun"] = "06";
monthMap["June"] = "06";
monthMap["Jul"] = "07";
monthMap["July"] = "07";
monthMap["Aug"] = "08";
monthMap["Sept"] = "09";
monthMap["Sep"] = "09";
monthMap["Oct"] = "10";
monthMap["Nov"] = "11";
monthMap["Dec"] = "12";
}
inline std::string processor::convertDate(std::string input) {
//Format: Mon Nov 08 17:41:23 +0000 2010
//To get to YYYY-MM-DD HH:MM:SS
std::stringstream newString(input);
std::string temp1;
std::string temp2;
// Read Day in txt, discard
newString >> temp1;
//Read month, convert to number
newString >> temp1;
temp2 = "-" + monthMap[temp1] + "-";
//Read Day in number
newString >> temp1;
temp2.append(temp1 + " ");
//Read TimeStamp
newString >> temp1;
temp2.append(temp1);
//Discard UTM adjustment
newString >> temp1;
//Read year
newString >> temp1;
//Add year to beginning of input
temp1.append(temp2);
return temp1;
}
I am trying to convert date-times that i am receiving into a particular format to insert into a MySQL database. The program is written in C++, and the following solution works but I feel it is horribly inefficient.
The input is : Mon Nov 08 17:41:23 +0000 2010
The desired output format is: YYYY-MM-DD HH:MM:SS
So for this example the output would be: 2010-11-08 17:41:23
I have included the relevant parts of the code.
//class variable
std::map<std::string, std::string> monthMap;
void processor::initializeMonthMap(){
monthMap["Jan"] = "01";
monthMap["Feb"] = "02";
monthMap["Mar"] = "03";
monthMap["Apr"] = "04";
monthMap["May"] = "05";
monthMap["Jun"] = "06";
monthMap["June"] = "06";
monthMap["Jul"] = "07";
monthMap["July"] = "07";
monthMap["Aug"] = "08";
monthMap["Sept"] = "09";
monthMap["Sep"] = "09";
monthMap["Oct"] = "10";
monthMap["Nov"] = "11";
monthMap["Dec"] = "12";
}
inline std::string processor::convertDate(std::string input) {
//Format: Mon Nov 08 17:41:23 +0000 2010
//To get to YYYY-MM-DD HH:MM:SS
std::stringstream newString(input);
std::string temp1;
std::string temp2;
// Read Day in txt, discard
newString >> temp1;
//Read month, convert to number
newString >> temp1;
temp2 = "-" + monthMap[temp1] + "-";
//Read Day in number
newString >> temp1;
temp2.append(temp1 + " ");
//Read TimeStamp
newString >> temp1;
temp2.append(temp1);
//Discard UTM adjustment
newString >> temp1;
//Read year
newString >> temp1;
//Add year to beginning of input
temp1.append(temp2);
return temp1;
}
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（3）
您正在解析字符串，幸运的是您可以通过简单的附加来构建输出。我不认为这会变得更有效率。
但是，您似乎可以使用eekg 将光标定位到一周中的某一天并进行UTM 调整。
http://www.cplusplus.com/reference/iostream/istream/seekg/
You're parsing the string and fortunately you can build the output by simple appends. I don't see this getting more efficient.
However, it appears as if you can use seekg to position the cursor past day of the week and UTM adjustment.
http://www.cplusplus.com/reference/iostream/istream/seekg/
使用 boost::date_time。您可以使用格式字符串以多种方式格式化输入和输出。
Use boost::date_time. You can format your input and output in a wide variety of ways with a format string.
如果您使用的是 POSIX 系统（即不是 Windows），则可以使用 strptime：
http://www.mkssoftware.com/docs/man3/strptime.3。 asp
这需要一个字符串并构建一个
struct tm，您可以通过 strftime 以任何所需的格式输出它。有一些 Windows 实现，但默认情况下不可用。在此处查看更多信息：将字符串转换为 C++ 中的日期
If you're on a POSIX system (i.e. not windows), you can use strptime:
http://www.mkssoftware.com/docs/man3/strptime.3.asp
This takes a string and builds a
struct tm, which you can output in any desired format via strftime.There are some windows implementations of this, but it's not available by default. See more here: Convert a string to a date in C++