请考虑这个 C++ 问题:
#include <cstdio>
#include <iostream>
#include <vector>
using namespace std;
class ParseURL{
private:
int qualify; // 0 means we qualify
public:
string node;
string service;
bool primary;
bool health;
string epoch;
// methods
ParseURL(string URL);
~ParseURL();
};
ParseURL::ParseURL(string URL){
vector<string> g2 = {"node", "service", "primary", "health", "epoch"};
for (string tag : g2){
auto found = URL.find(tag);
if ( found != string::npos ){
auto cut_from = found + 1 + tag.size() ;
auto meh = URL.substr(cut_from, URL.substr(cut_from).find("&") );
// is there a way we can avoid these lines below?
if (tag.find("node",0) == 0){
this->node = meh;
} else if (tag.find("service",0) == 0 ){
this->service = meh;
} else if (tag.find("epoch",0) == 0) {
this->epoch = meh;
} else if (tag.find("health",0) == 0){
this->health = (meh == "OK");
} else if (tag.find("primary",0) == 0 ){
this->primary == (this->node == meh);
}
}
}
}
ParseURL::~ParseURL(){
cout << "Tearing Down the class\n";
}
int main(){
char req[] = "GET /register?node=hostrpi3&service=potatoservice&primary=node1&health=OK&epoch=1559345106 HTTP";
string Request = req;
Request = Request.substr(Request.find_first_of(" ") );
Request = Request.substr(0, Request.find(" HTTP"));
ParseURL *a = new ParseURL(Request);
cout.width(12);
cout << "a->node: " << a->node << endl;
cout.width(12);
cout << "a->service: " << a->service << endl;
cout.width(12);
cout << "a->epoch: " << a->epoch << endl;
cout.width(12);
cout << "a->health: " << a->health << endl;
cout.width(12);
cout << "a->primary: " << a->primary << endl;
delete(a);
return 0;
}
我需要表示一个基于 URL 查询字符串的对象,我需要的标签以向量 g2 表示,正如您所看到的,我为ParseURL
从这些标签中。
O/P 看起来像:
a->node: hostrpi3
a->service: potatoservice
a->epoch: 1559345106
a->health: 1
a->primary: 0
Tearing Down the class
虽然这个版本可以用,但感觉还可以改进很多。尽管这一切都在 Vector 中,但我还是反复做tag.find
对于每个属性。我希望一定有更好的方法。你能指出正确的方向吗?谢谢!
Edit 1
谢谢,我按照建议更新了构造函数:
ParseURL::ParseURL(string URL){
char tags[10][100] = {"node", "service", "primary", "health", "epoch"};
int i = 0;
for (auto tag : tags){
auto found = URL.find(tag);
if ( found != string::npos ){
auto cut_from = found + 1 + strlen(tag);
auto tag_info = URL.substr(cut_from, URL.substr(cut_from).find("&") );
switch (i){
case 0:
this->node = tag_info;
break;
case 1:
this->service = tag_info;
break;
case 2:
this->primary = (this->node == tag_info);
break;
case 3:
this->health = (tag_info == "OK");
break;
case 4:
this->epoch = tag_info;
break;
}
}
i++;
}
}
例如,bash 提供变量的间接引用 - 也就是说,一个变量可能包含另一个变量的名称:
$ cat indirect.sh
#!/bin/bash
values="value1 value2"
value1="this is value1"
value2="this is value2"
for i in $values; do
echo "$i has value ${!i}"
done
$ ./indirect.sh
value1 has value this is value1
value2 has value this is value2
我希望类似的情况也存在,尽管如此,我在这里学到了宝贵的教训。谢谢你!