决定使用 CPP 库处理 xls 问题

lib_cpp/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.14)
+project(xlsx_reader VERSION 1.0.0 LANGUAGES CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+set(CMAKE_VISIBILITY_INLINES_HIDDEN ON)
+
+include(FetchContent)
+
+add_subdirectory(third_party/OpenXLSX)
+
+set(OPENXLSX_STATIC ON CACHE BOOL "Build OpenXLSX as static library")
+FetchContent_MakeAvailable(OpenXLSX)
+
+add_library(xlsx_reader SHARED src/xlsx_reader.cpp)
+
+target_include_directories(xlsx_reader PUBLIC include)
+
+target_link_libraries(xlsx_reader PRIVATE OpenXLSX::OpenXLSX)
+
+target_compile_definitions(xlsx_reader PRIVATE XLSX_BUILD_SHARED)

lib_cpp/include/xlsx_reader.h

@@ -0,0 +1,28 @@
+#ifndef XLSX_READER_H
+#define XLSX_READER_H
+
+#if defined(_WIN32)
+    #if defined(XLSX_BUILD_SHARED)
+        #define XLSX_API __declspec(dllexport)
+    #else
+        #define XLSX_API __declspec(dllimport)
+    #endif
+#elif defined(__GNUC__) || defined(__clang__)
+    #define XLSX_API __attribute__((visibility("default")))
+#else
+    #define XLSX_API
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+XLSX_API char* xlsx_read_first_sheet(const char* filepath);
+
+XLSX_API void xlsx_free_string(char* str);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

lib_cpp/src/xlsx_reader.cpp

@@ -0,0 +1,96 @@
+#include "xlsx_reader.h"
+
+#include <OpenXLSX/OpenXLSX.hpp>
+
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+static std::string jsonEscape(const std::string& s) {
+    std::string out;
+    out.reserve(s.size() + 2);
+    for (char c : s) {
+        switch (c) {
+            case '"':  out += "\\\""; break;
+            case '\\': out += "\\\\"; break;
+            case '\n': out += "\\n";  break;
+            case '\t': out += "\\t";  break;
+            case '\r': out += "\\r";  break;
+            default:
+                if (static_cast<unsigned char>(c) < 0x20) {
+                    char buf[8];
+                    std::snprintf(buf, sizeof(buf), "\\u%04x",
+                                  static_cast<unsigned char>(c));
+                    out += buf;
+                } else {
+                    out += c;
+                }
+        }
+    }
+    return out;
+}
+
+static std::string cellAsString(const OpenXLSX::XLCell& cell) {
+    using namespace OpenXLSX;
+    auto& val = cell.value();
+    switch (val.type()) {
+        case XLValueType::Integer:
+            return std::to_string(val.get<int64_t>());
+        case XLValueType::Float:
+            return std::to_string(val.get<double>());
+        case XLValueType::String:
+            return val.get<std::string>();
+        case XLValueType::Boolean:
+            return val.get<bool>() ? "true" : "false";
+        case XLValueType::Empty:
+        default:
+            return {};
+    }
+}
+
+extern "C" XLSX_API char* xlsx_read_first_sheet(const char* filepath) {
+    if (!filepath) return nullptr;
+
+    try {
+        OpenXLSX::XLDocument doc;
+        doc.open(filepath);
+
+        auto wks = doc.workbook().worksheet(1);
+
+        std::string json;
+        json += '[';
+
+        bool firstRow = true;
+        for (auto& row : wks.rows()) {
+            if (!firstRow) json += ',';
+            json += '[';
+
+            bool firstCell = true;
+            for (auto& cell : row.cells()) {
+                if (!firstCell) json += ',';
+                json += '"';
+                json += jsonEscape(cellAsString(cell));
+                json += '"';
+                firstCell = false;
+            }
+
+            json += ']';
+            firstRow = false;
+        }
+
+        json += ']';
+        doc.close();
+
+        char* result = static_cast<char*>(std::malloc(json.size() + 1));
+        if (result) {
+            std::memcpy(result, json.c_str(), json.size() + 1);
+        }
+        return result;
+    } catch (const std::exception&) {
+        return nullptr;
+    }
+}
+
+extern "C" XLSX_API void xlsx_free_string(char* str) {
+    std::free(str);
+}