可购买链接URL生成器无法正确填充购物车问题求助

问题背景 #

为网站编写购物车链接生成代码，谷歌表格版本可正常生成有效链接，但C++控制台程序和QT程序生成的链接仅能打开购物车，无法填充商品或仅填充第一个商品。生成流程为：构造JSON格式商品数据→URL百分编码→Base64编码→拼接成最终链接。

对比测试结果 #

已确认Base64编码结果与谷歌表格版本存在差异：

• 控制JSON字符串：

{"products":[{"id":"606625996","quantity":"2","options":{"size":"10 inch"}},{"id":"606625996","quantity":"6","options":{"size":"6 inch"}}]}

• 谷歌表格生成的有效Base64输出：

JTdCJTIycHJvZHVjdHMlMjIlM0ElNUIlN0IlMjJpZCUyMiUzQSUyMjYwNjYyNTk5NiUyMiUyQyUyMnF1YW50aXR5JTIyJTNBJTIyMiUyMiUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJzaXplJTIyJTNBJTIyMTAlMjBpbmNoJTIyJTdEJTdEJTJDJTdCJTIyaWQlMjIlM0ElMjI2MDY2MjU5OTYlMjIlMkMlMjJxdWFudGl0eSUyMiUzQSUyMjYlMjIlMkMlMjJvcHRpb25zJTIyJTNBJTdCJTIyc2l6ZSUyMiUzQSUyMjYlMjBpbmNoJTIyJTdEJTdEJTVEJTdE

• 控制台程序无效Base64输出：

JTdCJTIycHJvZHVjdHMlMjIlM0ElNUIlN0IlMjJpZCUyMiUzQSUyMjYwNjYyNTk5NiUyMiUyQyUyMnF1YW50aXR5JTIyJTNBJTIyMiUyMiUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJzaXplJTIyJTNBJTIyMTAlMjBpbmNoJTIyJTdEJTdEJTJDJTdCJTIycHJvZHVjdHMlMjIlM0ElNUIlN0IlMjJpZCUyMiUzQSUyMjYwNjYyNTk5NiUyMiUyQyUyMnF1YW50aXR5JTIyJTNBJTIyNiUyMiUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJzaXplJTIyJTNBJTIyNiUyMGluY2glMjIlN0QlN0QlNUQlN0A=

• QT程序无效Base64输出：

JTdCJTIycHJvZHVjdHMlMjIlM0ElNUIlN0IlMjJpZCUyMiUzQSUyMjYwNjYyNTk5NiUyMiUyQyUyMnF1YW50aXR5JTIyJTNBJTIyMiUyMiUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJzaXplJTIyJTNBJTIyMTAlMjBpbmNoJTIyJTdEJTdEJTJDJTdCJTIycHJvZHVjdHMlMjIlM0ElNUIlN0IlMjJpZCUyMiUzQSUyMjYwNjYyNTk5NiUyMiUyQyUyMnF1YW50aXR5JTIyJTNBJTIyNiUyMiUyQyUyMm9wdGlvbnMlMjIlM0ElN0IlMjJzaXplJTIyJTNBJTIyNiUyMGluY2glMjIlN0QlN0QlNUQlN0Q=

代码实现 #

主程序代码 #

#include<iostream>
#include<fstream>
#include<sstream>
#include<list>
#include<string>
#include<base64.h>
#include<encoder.h>
#include<infoFind.h>
#include<escapencode.h>

using namespace std;

int main()
{   
    list <string> choices;
    string done="";
    string internid="";
    string quant="";
    string type="";
    string option="";
    string open="https://www.sustainhydro.com/online-store/!/~/cart/create=";
    string body1="{\"products\":[{\"id\":\"";
    string body2="\",\"quantity\":\"";
    string body3="\",\"options\":{\"";
    string body4"\":\"";
    string body5"\"}}";
    string close="]}";
    string delim=",";
    string temp="";
    string comp="";
    string input="";

    while (done != "n")
    { 
        catinfo();

        cout<< "" << '\n';
        cout << "Enter Internal Id: ";
        cin >> internid;
        cout << "Enter Quantity: ";
        cin >> quant;
        cout << "Enter Type: ";
        cin >> type;
        cout << "Enter Option: ";
        cin.ignore();
        getline(cin,option);

        cout <<""<<'\n';
        cout << "Do you have another SKU: y , n : ";
        cin >> done;

        temp=body1+internid+body2+quant+body3+type+body4+option+body5;
        choices.push_back(temp);
        choices.push_back(delim);

        if (done == "y")
        {
            continue;
        }  

        if (done == "n")
        {
            choices.pop_back();
            choices.push_back(close);
            for (auto i : choices)
            {
                comp+=i;
            }

            if (!comp.empty() && (comp.back() == '\n' || comp.back() == '\0'))
            {
                comp.pop_back();
            }

            comp = escape(comp);
            cout << comp << endl;
            comp=base64_encode(comp);
            cout << comp << endl;

            cout << '\n';
            cout <<  "THIS IS YOUR URL:" << endl;
            cout << '\n';
            cout << open;
            cout << comp;
            cout << "" << '\n';
            cout << "" << '\n';
            cout << "Copy and Paste the URL From Here";
            cout << "" << '\n';
            break;
        }
    }
    return 0;
}

escapeencode.h代码 #

#include<iterator>
#include<algorithm>
#include<iostream>
#include<string>
#include<list>

using namespace std;

string space="%20";
string colon="%3A";
string bracko="%5B";
string brackc="%5D";
string braceo="%7B";
string bracec="%7D";
string quote="%22";
string comma="%2C";

string escape(string json)
{
    list<string>temp;
    string result="";
    char chr;
    for(char i : json)
    {
        chr=i;
        string newchr(1,chr);
        if(newchr == "[")
        {
            newchr=bracko;
        }
        if(newchr == "]")
        {
            newchr=brackc;
        }
        if(newchr == " ")
        {
            newchr=space;
        }
        if(newchr == ":")
        {
            newchr=colon;
        }
        if(newchr == "{")
        {
            newchr=braceo;
        }
        if(newchr == "}")
        {
            newchr=bracec;
        }
        if(newchr == "\"")
        {
            newchr=quote;
        }
        if(newchr == ",")
        {
            newchr=comma;
        }
        temp.push_back(newchr);
    }
    for(string i : temp)
    {
        result=result+i;
    }
    return result;
}

base64.h代码 #

#include <algorithm>
#include <array>
#include <cctype>
#include <string>

const std::array<char, 64> base64_chars = {
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
    'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

std::string base64_encode(const std::string& input) {
    std::string output;
    int val = 0, valb = -6;
    for (unsigned char c : input) {
        val = (val << 8) + c;
        valb += 8;
        while (valb >= 0) {
            output.push_back(base64_chars[(val >> valb) & 0x3F]);
            valb -= 6;
        }
    }
    if (valb > -6) output.push_back(base64_chars[(val << (6 + valb)) & 0x3F]);
    while (output.size() % 4) output.push_back('=');
    return output;
}

核心问题与修正方案 #

问题根源 #

主程序的JSON拼接逻辑错误：每个商品都会生成完整的{"products":[{"id":...}]}片段，最终拼接后的结构变成{"products":[{"id":...}]},{"products":[{"id":...}]}]，完全不符合正确的JSON格式（正确格式应为{"products":[{"id":...},{"id":...}]}），导致后端无法解析商品列表。

修正方案 #

调整JSON拼接逻辑，只在开头添加一次"products"数组的起始部分，每个商品仅生成单个商品的JSON对象，最后统一闭合数组：

int main()
{   
    list <string> choices;
    string done="";
    string internid="";
    string quant="";
    string type="";
    string option="";
    string open="https://www.sustainhydro.com/online-store/!/~/cart/create=";
    // 仅在开头添加一次products数组起始
    string json_start="{\"products\":[";
    // 单个商品的模板
    string item_template="{\"id\":\"%s\",\"quantity\":\"%s\",\"options\":{\"%s\":\"%s\"}}";
    string json_end="]}";
    string delim=",";
    string temp="";
    string comp="";

    // 先添加起始部分
    choices.push_back(json_start);

    while (done != "n")
    { 
        catinfo();

        cout<< "" << '\n';
        cout << "Enter Internal Id: ";
        cin >> internid;
        cout << "Enter Quantity: ";
        cin >> quant;
        cout << "Enter Type: ";
        cin >> type;
        cout << "Enter Option: ";
        cin.ignore();
        getline(cin,option);

        cout <<""<<'\n';
        cout << "Do you have another SKU: y , n : ";
        cin >> done;

        // 构造单个商品的JSON字符串
        char item_buf[256];
        sprintf(item_buf, item_template.c_str(), internid.c_str(), quant.c_str(), type.c_str(), option.c_str());
        temp = item_buf;
        choices.push_back(temp);
        choices.push_back(delim);

        if (done == "y")
        {
            continue;
        }  

        if (done == "n")
        {
            // 移除最后一个多余的逗号，添加结束部分
            choices.pop_back();
            choices.push_back(json_end);
            for (auto i : choices)
            {
                comp+=i;
            }

            comp = escape(comp);
            cout << comp << endl;
            comp=base64_encode(comp);
            cout << comp << endl;

            cout << '\n';
            cout <<  "THIS IS YOUR URL:" << endl;
            cout << '\n';
            cout << open;
            cout << comp;
            cout << "" << '\n';
            cout << "" << '\n';
            cout << "Copy and Paste the URL From Here";
            cout << "" << '\n';
            break;
        }
    }
    return 0;
}

调整后生成的JSON结构与谷歌表格版本一致，后续的URL编码和Base64编码结果也会匹配，即可生成有效链接。

内容的提问来源于stack exchange，提问作者Wannabe_coder