【QT 網絡編程】HTTP協議(二)

文章目錄

🌟1.概述
🌟2.代碼結構概覽
🌟3.代碼解析
- 🌸Http_Api_Manager - API管理類
- 🌸Http_Request_Manager- HTTP請求管理類
- 🌸ThreadPool - 線程池
- 🌸TestWindow- 測試類
🌟4.運行效果
🌟5.總結

🌟1.概述

本文將基于Qt框架，講解如何實現一個高效的HTTP客戶端，并分析其核心代碼實現原理。
Qt 提供了 QNetworkAccessManager 作為HTTP請求的核心組件，同時結合 QNetworkRequest 和 QNetworkReply，可以完成基本的HTTP通信。此外，為了提高并發處理能力，我們還會結合 ThreadPool 對請求的響應進行異步管理。

🌟2.代碼結構概覽

該HTTP客戶端主要由以下幾個核心組件組成：

Http_Api_Manager：對外提供API調用的管理類，封裝業務邏輯。
Http_Request_Manager：具體負責發送HTTP請求。
ThreadPool：線程池，用于異步處理請求，提高并發能力。
TestWindow：測試類，用于模擬多次請求，測試出http請求的性能數據。

🌟3.代碼解析

🌸Http_Api_Manager - API管理類

class Http_Api_Manager : public QObject
{Q_OBJECTstruct ApiResponse {// 通用響應數據結構解析,根據自定義響應報文解析int code;QString message;QJsonValue data;static ApiResponse fromJson(const QJsonDocument& doc);};public:static Http_Api_Manager* getInstance();// 測試API方法，可以考慮抽象出基類請求，外部調用公共接口，內部進行API類型區分void updateAllVoteItem(const QString &userGuid, const QString &conferenceGuid, int pageNum, int pageSize, int requestIndex = -1);signals://響應處理完畢信號void allVoteItemUpdated(bool success,int index = 0);void requestError(const QString& errorMessage);private:static Http_Api_Manager* instance;//單例std::unique_ptr<ThreadPool> m_threadPool;//線程池class Private;//聲明私有類，將具體實現隱藏std::unique_ptr<Private> d;//指向私有實現的指針private:explicit Http_Api_Manager(QObject *parent = nullptr);~Http_Api_Manager();// 基礎JSON解析函數，將業務響應處理函數作為傳參回調void processResponse(const QByteArray &response,std::function<void(const QJsonDocument&)> handler);                     // 業務響應處理函數void processVoteListResponse(const QJsonDocument& doc,const int &requestIndex = -1);
};

將API管理類實現為單例，方便全局調用以及對HTTP請求的管理。新增接口只需實現具體的請求函數、請求響應的業務處理函數以及處理完畢的信號函數。對于響應的業務處理會放入子線程異步執行。

//具體的API請求函數
void Http_Api_Manager::updateAllVoteItem(const QString &userGuid, const QString &conferenceGuid, int pageNum, int pageSize, int requestIndex)
{//查詢傳參QMap<QString, QString> queryParams = { {"guid", conferenceGuid}, {"pageNum", QString::number(pageNum)}, {"pageSize", QString::number(pageSize)} };//封裝一個請求任務Http_Request_Task task(Http_Request_Task::GET, "/api/client/voting/findVotingStatisticList", queryParams);//調用Http_Request_Manager的公共接口，并傳入響應處理回調函數Http_Request_Manager::getInstance()->sendRequest(task, [this, requestIndex](const QByteArray& response) {m_threadPool->enqueue([this, response, requestIndex]() {processResponse(response, std::bind(&Http_Api_Manager::processVoteListResponse, this, std::placeholders::_1, requestIndex));});});
}
//具體的響應業務處理函數
void Http_Api_Manager::processVoteListResponse(const QJsonDocument& doc, const int &requestIndex) {ApiResponse response = ApiResponse::fromJson(doc);if (response.code != 0) {emit requestError(response.message);return;}if (response.message.contains("Success")) {QJsonArray voteItems = response.data.toArray();// 在這里可以進行具體的數據轉換和處理if(requestIndex!=-1)emit allVoteItemUpdated(true,requestIndex);elseemit allVoteItemUpdated(true);} else {emit requestError("Invalid vote list data format");}
}

🌸Http_Request_Manager- HTTP請求管理類

class Http_Request_Task {//請求任務封裝類
public:enum RequestType {//請求類型GET,POST,POST_FILE};Http_Request_Task(RequestType type, const QString& api,const QMap<QString, QString>& params = {}, const QByteArray& data = QByteArray()): m_tType(type), m_sApi(api), m_mRequestParams(params), m_bData(data) {}//構造RequestType type() const { return m_tType; }QString api() const { return m_sApi; }QMap<QString, QString> params() const { return m_mRequestParams; }QByteArray data() const { return m_bData; }private:RequestType m_tType;//請求類型 GET|POST|POST_FILEQString m_sApi;//api接口QMap<QString, QString> m_mRequestParams;//請求傳參QByteArray m_bData;//header傳參
};typedef std::function<void(const QByteArray&)> ResponseCallback;//聲明請求回調類型
class Http_Request_Manager : public QObject//請求管理類
{Q_OBJECT
public:static Http_Request_Manager* getInstance(QObject *parent=nullptr);//單例構造static QNetworkAccessManager* networkAccessManager() {return getInstance()->m_pSharedNAM;}void sendRequest(const Http_Request_Task& task, ResponseCallback callback);//發送請求，傳入task以及處理函數指針void setServerAddress(const QString &newServerAddress);//設置服務器地址private:static Http_Request_Manager* instance;//單例QNetworkAccessManager *m_pSharedNAM = nullptr;//唯一網絡處理實例QString m_sServerAddress;//服務器地址QMap<QNetworkReply*, ResponseCallback> m_mReplyCallbacks;//網絡請求與回調的映射private:Http_Request_Manager(QObject *parent=nullptr);~Http_Request_Manager();QUrl constructURL(const QString& api, const QUrlQuery& query);void setSSLConfig();QNetworkReply* sendGetRequest(const QNetworkRequest& request);QNetworkReply* sendPostRequest(const QNetworkRequest& request, const QByteArray& data);QNetworkReply* sendFileRequest(const QNetworkRequest& request, const QString& filePath);
};

將HTTP請求管理類實現為單例，為了復用QNetworkAccessManager實例。QNetworkAccessManager內部維護連接池以及線程池默認異步調用，如果創建多個實例，tcp連接可能無法復用。

//對外暴露功能請求接口，內部實現請求區分
void Http_Request_Manager::sendRequest(const Http_Request_Task &task, ResponseCallback callback)
{QUrlQuery query;for (auto it = task.params().constBegin(); it != task.params().constEnd(); ++it) {query.addQueryItem(it.key(), it.value());}QUrl url = constructURL(task.api(), query);QNetworkRequest request(url);//啟用 HTTP/2 或 Pipelining，提高并發能力。//默認http1，Qt的HTTP連接池限制同一主機的最大并發連接數。request.setAttribute(QNetworkRequest::HTTP2AllowedAttribute, true);request.setAttribute(QNetworkRequest::HttpPipeliningAllowedAttribute, true);QNetworkReply* reply = nullptr;switch (task.type()) {case Http_Request_Task::GET:reply = sendGetRequest(request);break;case Http_Request_Task::POST:reply = sendPostRequest(request, task.data());break;case Http_Request_Task::POST_FILE:reply = sendFileRequest(request, QString(task.data()));break;}if (reply) {m_mReplyCallbacks.insert(reply, callback);connect(reply, &QNetworkReply::finished, this, [this, reply]() {if (reply->error() == QNetworkReply::NoError) {QByteArray responseData = reply->readAll();if (m_mReplyCallbacks.contains(reply)) {m_mReplyCallbacks[reply](responseData);m_mReplyCallbacks.remove(reply);}}reply->deleteLater();});}
}

🌸ThreadPool - 線程池

class ThreadPool {
public:ThreadPool(size_t);template<class F, class... Args>auto enqueue(F&& f, Args&&... args) -> std::future<typename std::result_of<F(Args...)>::type>;~ThreadPool();
};

C++11語法的線程池實現在Github是開源的，非常牛杯一的代碼。

🌸TestWindow- 測試類

class TestWindow : public QObject
{Q_OBJECTstruct RequestMetrics {qint64 requestStartTime; // 請求開始時間qint64 requestEndTime;   // 請求結束時間qint64 processingTime;  // 請求耗時bool success;           // 是否成功};
public:explicit TestWindow(QObject *parent = nullptr);void testRequest(int loopCount = 1); // 添加循環次數參數signals:void testCompleted(int totalRequests, int successfulRequests, int failedRequests, qint64 totalTime, const QList<RequestMetrics>& metrics);private:QElapsedTimer m_testTimer;int m_requestCount;int m_concurrentRequests;int m_completedRequests;int m_successfulRequests;int m_failedRequests;QList<RequestMetrics> m_requestMetrics; // 存儲所有請求的執行情況private:QString formatTime(const qint64 &timestamp);
};

在調用類中，只需要初始化Http_Request_Manager服務器地址，發出具體請求以及連接響應處理信號。

Http_Request_Manager::getInstance()->setServerAddress("192.168.42.101");//設置服務器地址auto* apiManager = Http_Api_Manager::getInstance();
connect(apiManager, &Http_Api_Manager::allVoteItemUpdated, this, [=](bool success, int requestIndex) {qint64 endTime = QDateTime::currentMSecsSinceEpoch();// 根據請求索引獲取對應的 RequestMetrics 對象if (requestIndex >= 0 && requestIndex < m_requestMetrics.size()) {RequestMetrics& metrics = m_requestMetrics[requestIndex];metrics.requestEndTime = endTime;metrics.processingTime = endTime - metrics.requestStartTime;metrics.success = success;m_completedRequests++;m_concurrentRequests--;if (success) {m_successfulRequests++;} else {m_failedRequests++;}LogDebug << "Request" << (requestIndex + 1) << "completed. Success:" << success<< "Start Time:" << metrics.requestStartTime<< "End Time:" << metrics.requestEndTime<< "Processing Time:" << metrics.processingTime << "ms";// 如果所有請求完成，發出測試完成信號if (m_completedRequests == m_requestCount) {qint64 totalTime = m_testTimer.elapsed();emit testCompleted(m_requestCount, m_successfulRequests, m_failedRequests, totalTime, m_requestMetrics);}}});
void TestWindow::testRequest(int loopCount)
{auto* apiManager = Http_Api_Manager::getInstance();m_testTimer.start(); // 開始計時m_requestCount = loopCount; // 設置總請求數m_completedRequests = 0; // 重置完成請求數m_successfulRequests = 0; // 重置成功請求數m_failedRequests = 0; // 重置失敗請求數m_requestMetrics.clear(); // 清空之前的請求記錄for (int i = 0; i < loopCount; ++i) {m_concurrentRequests++;RequestMetrics metrics;metrics.requestStartTime = QDateTime::currentMSecsSinceEpoch(); // 記錄請求開始時間m_requestMetrics.append(metrics); // 存儲當前請求的開始時間// 發送請求
//        apiManager->updateAllVoteItem("e7cb3697-74ac-4b48-a472-dab5637e7968", "76050537-f63e-41db-a060-949d9d9def52", 1, 100,i);apiManager->updateAllVoteItem("e7cb3697-74ac-4b48-a472-dab5637e7968", "e92647e1-e81a-4c14-9678-10275a81f9c7", 1, 100,i);}
}