URL中符号意义
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/ 分隔目录和子目录
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?分隔实际的URL和参数
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& URL中指定的参数间的分隔符
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= URL中指定的参数的值
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+ 表示空格(在URL中不能使用空格)
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# 表示书签
在RESTful风格的API中常见的URL样式:
- 带时间路径的URL
http://127.0.0.1:8080/Date/20230323173037 - 使用 ? 符号的分隔符
http://127.0.0.1:8080/Hld?date=20230323173037 - 使用 & 符号带2个参数
http://127.0.0.1:8080/Hld?date=20230323173037&date=20230366
代码演示获取参数:
#include <iostream>
#include <string>
#include <map>
#include <httplib.h>using namespace std;
using namespace httplib;int main()
{multimap<string, string> m = { {"HTTP0.9", "1991"}, {"HTTP1.0", "1996"}, {"HTTP1.1", "1999"} };for (multimap<string, string>::iterator it = m.begin(); it != m.end(); ++it){cout << "[" << (*it).first << ", " << (*it).second << "]" << endl;}Server svr;svr.set_keep_alive_max_count(10);svr.set_keep_alive_timeout(10);svr.set_payload_max_length(1024 * 1024 * 512);svr.Get("/Hld", [&](const Request& req, Response& res) {cout << req.matches[0] << endl;cout << "params.size() = " << req.params.size() << endl;string context;for(std::multimap<std::string, std::string>::const_iterator it = req.params.begin(); it != req.params.end(); ++it){string params = it->first + " = " + it->second;cout << params << endl;context += params += "\n";}res.set_content(context, "text/plain");});svr.set_error_handler([&](const Request& req, Response& res) {auto fmt = "<p>Error Status: <span style='color:red;'>%d</span></p>";char buf[BUFSIZ];snprintf(buf, sizeof(buf), fmt, res.status);res.set_content(buf, "text/html");});// Loggingsvr.set_logger([&](const Request& req, const Response& res) {for(std::multimap<std::string, std::string>::const_iterator it = req.params.begin(); it != req.params.end(); ++it){string params = it->first + "=" + it->second;cout <<"[" << __FILE__ << ":" << __LINE__ << "] " << it->first << "=" << it->second << endl;}});svr.listen("0.0.0.0", 8080);return 0;
}
由于 ? 符号是分隔实际的URL和参数,所以 req.matches[0] 并不能获取到URL的参数,只能获得带路径的 / 符号后面的数据,而 req.params 才是获取URL的参数,理解URL才是理解代码的关键。