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mongocxx安装和使用

发表于 分类于

https://www.cnblogs.com/mxnote/p/17098385.html

mongodb C驱动安装 mongodb C++驱动安装

mongo-cxx-driver github源码地址

mongodb的API文档

mongodb安装

官方教程：https://www.mongodb.com/docs/manual/tutorial/install-mongodb-on-red-hat/

CentOS 7 yum安装MongoDB - 斌言 - 博客园 (cnblogs.com)

1、配置MongoDB的yum源（这里使用阿里云的源），创建文件/etc/yum.repos.d/mongodb-org-6.0.repo，并输入以下内容

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[mngodb-org]
name=MongoDB Repository
baseurl=http://mirrors.aliyun.com/mongodb/yum/redhat/$releasever/mongodb-org/6.0/x86_64/
gpgcheck=0
enabled=1
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$ yum update -y   # 更新yum
$ yum install mongodb-org -y   # 下载MongoDB
$ rpm -qa | grep mongodb      # 查看安装的mongodb组件
$ systemctl start mongod  # 开启mongodb服务

C++驱动安装

https://www.mongodb.com/docs/drivers/cxx/#mongodb-compatibility

https://mongocxx.org/mongocxx-v3/installation/

安装mongocxx 3.8，对应mongodb 6.0

安装过程中可能会因为缺少依赖而报错，只要根据错误信息安装相关依赖即可

官方标注的前提条件

  • Any standard Unix platform, or Windows 7 SP1+
  • A compiler that supports C++11 (gcc, clang, or Visual Studio)
  • CMake 3.2 or later
  • boost headers (optional)

安装Cmake

根据实际需要安装对应的Cmake

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$ wget https://github.com/Kitware/CMake/releases/download/v3.27.1/cmake-3.27.1.tar.gz
$ tar zxvf cmake-3.27.1.tar.gz
$ cd cmake-3.27.1
$ ./bootstrap
$ make
$ make install
$ cmake --version  # 查看版本

安装mongoc

详细过程和解释参照官网：http://mongoc.org/libmongoc/current/installing.html

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$ yum install mongo-c-driver-devel
$ yum install libbson-devel
$ yum install openssl-devel cyrus-sasl-devel libbsd-devel libzstd-devel bind-utils libicu-devel
$ wget https://github.com/mongodb/mongo-c-driver/releases/download/1.24.2/mongo-c-driver-1.24.2.tar.gz
$ tar xzf mongo-c-driver-1.24.2.tar.gz
$ cd mongo-c-driver-1.24.2
$ mkdir cmake-build
$ cd cmake-build
$ cmake -DENABLE_AUTOMATIC_INIT_AND_CLEANUP=OFF ..

cmake成功显示如下：

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-- Build files have been written to: /home/user/mongo-c-driver-1.24.2/cmake-build

问题1）-- Looking for ASN1_STRING_get0_data in /usr/lib64/libcrypto.so - not found

  • 当openssl <= 1.0.1时，ASN1_STRING_get0_data该方法不存在，作为替代是ASN1_STRING_data方法
  • 当openssl > 1.0.1时，ASN1_STRING_get0_data方法存在，但实际出问题的时候，服务器版本是Open SSL1.0.2.k，建议安装之后的版本

参考：https://www.bbsmax.com/A/xl56YnWxJr/

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# 安装1.1.0f版本
$ wget http://www.openssl.org/source/openssl-1.1.0f.tar.gz
$ tar zxvf openssl-1.1.0f.tar.gz
$ cd openssl-1.1.0f
$ ./config --prefix=/usr/local/ssl
$ make && make install
# 将旧的openssl执行文件及目录重命令
$ mv -f /usr/bin/openssl /usr/bin/openssl.old
$ mv -f /usr/include/openssl /usr/include/openssl.old
# 修改软链，指向新版本的openssl路径
$ ln -s /usr/local/ssl/bin/openssl /usr/bin/openssl
$ ln -s /usr/local/ssl/include/openssl /usr/include/openssl
# 将指向libcrypto.so.1.0.2k的软链接删除，创建指向libcrypto.so.1.1的软链接
$ rm /usr/lib64/libcrypto.so
$ ln -s /usr/local/ssl/lib/libcrypto.so.1.1 /usr/lib64/libcrypto.so
# 查看是否有ASN1_STRING_get0_data方法
$ nm /usr/lib64/libcrypto.so | grep ASN1_STRING_get0_data
0000000000088f20 T ASN1_STRING_get0_data
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$ cmake --build .
$ cmake --build . --target install

测试mongoc是否安装成功：

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#include <mongoc/mongoc.h>
#include <stdio.h>
int main() {
    mongoc_init();
    printf("libmongoc version: %s\n", mongoc_get_version());
    mongoc_cleanup();
    return 0;
}
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$ gcc test_mongoc.c -I/usr/local/include/libmongoc-1.0 -I/usr/local/include/libbson-1.0 -L/usr/local/lib64 -lmongoc-1.0 -lbson-1.0
$ ./a.out
libmongoc version: 1.3.6

安装boost库

1、使用yum安装，版本可能不合适（不推荐）

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$ yum install boost boost-devel boost-doc

2、源码安装（国内下载巨慢，建议魔法上网）

去官网选择对应版本下载：https://www.boost.org/users/history/ ，我下载的为1.70.0版本：https://www.boost.org/users/history/version_1_70_0.html

注意：

安装boost库的指令流程，下载对应版本的压缩包后：

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$ tar zxvf boost_1_70_0.tar.gz 
$ cd boost_1_70_0
$ yum install bzip2 bzip2-devel xz xz-devel
$ ./bootstrap.sh --prefix=/usr/local/boost   # 指定安装目录，需要自己创建
$ ./b2
The Boost C++ Libraries were successfully built!
$ ./b2 install

安装过程中可能会出一些问题，根据提示信息处理，示例如下：

1）缺少Boost库的Unicode/ICU支持，安装ICU库yum install -y libicu-devel

image-20230730105731103

2）

image-20230730110116673

在/etc/ld.so.conf文件中追加：/usr/local/boost/lib

测试是否安装成功：g++ -o test test.cpp -I /usr/local/boost/include/ 

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#include <iostream>
#include <boost/algorithm/string.hpp>

int main()
{
    std::string str = "hello, boost library!";
    boost::algorithm::to_upper(str);
    std::cout << str << std::endl;
    return 0;
}

安装mongocxx

注意GCC的版本要支持C++17，建议使用GCC7以后的版本

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$ wget https://github.com/mongodb/mongo-cxx-driver/releases/download/r3.8.0/mongo-cxx-driver-r3.8.0.tar.gz
$ tar -xzf mongo-cxx-driver-r3.8.0.tar.gz
$ cd mongo-cxx-driver-r3.8.0/build
$ cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr/local
$ cmake --build . --target EP_mnmlstc_core
$ cmake --build .
$ cmake --build . --target install
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$ echo '/usr/local/lib64' >> /etc/ld.so.conf   # 增加libmongocxx.so._noabi的链接路径
$ find /usr -name libmongocxx*.pc   # 查找libmongocxx.pc所在位置
/usr/local/lib64/pkgconfig/libmongocxx.pc
$ export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig   # 设置pkg-config查找pc文件路径
$ pkg-config --cflags --libs libmongocxx    # 
-I/usr/local/include/mongocxx/v_noabi -I/usr/local/include/bsoncxx/v_noabi  -L/usr/local/lib64 -lmongocxx -lbsoncxx

mongodb测试

g++ -o testmongo testmongo.cpp $(pkg-config --cflags --libs libmongocxx) 

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#include <iostream>
#include <memory>
#include <cstring>

#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
#include <mongocxx/exception/exception.hpp>
#include <bsoncxx/builder/stream/document.hpp>
#include <bsoncxx/json.hpp>

using namespace std;
using bsoncxx::builder::stream::document;
using bsoncxx::builder::stream::finalize;

void printIfAge(mongocxx::client& client, int age) {
    auto collection = client["tutorial"]["persons"];
    auto cursor = collection.find(document{} << "age" << age << finalize);
    for (auto&& doc : cursor) {
        cout << doc["name"].get_utf8().value.to_string() << endl;
    }
}

void run(const char* dbhost) {
    mongocxx::instance instance{}; // Required to initialize the driver
    mongocxx::client client{mongocxx::uri{dbhost}};
    cout << "connected ok" << endl;
    auto collection = client["tutorial"]["persons"];
    collection.insert_one(document{} << "name" << "Joe" << "age" << 33 << finalize);
    collection.insert_one(document{} << "name" << "Jane" << "age" << 40 << finalize);
    collection.insert_one(document{} << "name" << "Abe" << "age" << 33 << finalize);
    collection.insert_one(document{} << "name" << "Samantha" << "age" << 21 << "city" << "Los Angeles" << "state" << "CA" << finalize);
    collection.create_index(document{} << "age" << 1 << finalize);
    cout << "count: " << collection.count_documents({}) << endl;
    auto cursor = collection.find({});
    for (auto&& doc : cursor) {
        cout << bsoncxx::to_json(doc) << endl;
    }
    cout << "\nprintifage:\n";
    printIfAge(client, 33);
}

int main(int argc, char *argv[]) {
    const char* dbhost = "mongodb://localhost:27017";
    if (argc == 2) {
        dbhost = argv[1];
        printf("connect to dbhost:[%s]\n", dbhost);
    } else {
        printf("connect to dbhost:[%s]\n", dbhost);
        printf("if you need to connect to a remote service, please input IP address!\n");
    }
    try {
        run(dbhost);
    } catch (const mongocxx::exception& e) {
        cout << "caught " << e.what() << endl;
    }
    return 0;
}

GirdFS示例

源自黑马教程

需求总体描述：开发类似于网盘功能,支持文件(图片,视频,mp3等)的上传和下载.mongodb的优势

功能需求：支持多用户

  1. 用户的校验,必须是注册用户,用户名和密码正确才能上传和下载.(注册部分正常需要web前端开发,该案列不做注册部分功能,直接在mysql的用户表增加记录即可).
  2. 查看登陆用户上传的文件信息.(支持命令行的方式查看即可,不需要做web前端),实现管理台.
  3. 上传文件
  4. 下载上传过的文件到本地.
  5. 删除上传的文件.(可根据情况是否添加,不是必须)

技术实现要求：Mysql+mongo

  1. 用mysql存储用户的信息,文件上传和下载的对应关系(本地和mongo中文件的对应关系)
  2. Mongo存放文件.

MySQL建库建表：

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create database ods character set utf8;

use ods;

// 用户信息表：用户id，用户姓名，密码，手机号，公司，邮箱，备注
create table t_user_info(
    user_id varchar(30),
    user_name varchar(50),
    pass_word varchar(16),
    remark varchar(100)
);

// 文件信息表：本地文件名，文件类型，大小，上传时间，修改时间，下载次数，用户id，mongo文件名，备注
create table t_file_info(
    file_id int primary key auto_increment,
    local_file_name varchar(50),
    mongo_file_name varchar(50),
    file_size int,
    upload_date timestamp,
    user_id varchar(30),
    remark varchar(100)
);


insert into t_user_info values('yekai','叶开','123','bianchenglangzi');
insert into t_user_info values('fuhongxue','傅红雪','456','bianchenglangzi');

// 在文件信息表中增加上传状态：上传中，上传成功
alter table t_file_info add column status varchar(2);

实现：

  1. CMysql.h和CMysql.cpp实现和mysql的交互
  2. CMongo.h和CMongo.cpp实现和mongodb的交互
  3. main.cpp控制台，和用户交互

操作指令：

  • 上传 upload srcfile mongofile
  • 下载 download mongofile desfile
  • 查看 list
  • 退出 quit
  • 删除 delete mongofile localfile

代码：

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// CMysql.h
#pragma once
class CMysql
{
public:
	CMysql();
	~CMysql();
	int UserLogin(const char* User, const char* Passwd);
	int ListFileInfo(const char* User);
	int UploadFile(const char* User, const char* LocalFile, const char* MongoFile);
	int UpdateFileInfo(int FileSize, const char* User, const char* LocalFile, const char* MongoFile);
};
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// CMysql.cpp
#include "CMysql.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mysql.h>

MYSQL* mysql = NULL;

CMysql::CMysql()
{
	mysql = mysql_init(NULL);
	if (mysql == NULL)
	{
		printf("mysql init err\n");
		exit(1);
	}
	mysql = mysql_real_connect(mysql, "localhost", "root", "123456", "ods", 0, NULL, 0);
	if (mysql == NULL)
	{
		printf("mysql connect err\n");
		exit(1);
	}
}

CMysql::~CMysql()
{
	if (mysql) 
	{
		mysql_close(mysql);
	}
}

//用户登录
int CMysql::UserLogin(const char* User, const char* Passwd)
{
	// select * from t_user_info where user_id='yekai' and pass_word='123';
	if (strstr(Passwd, " or "))  // select * from t_user_info where user_id='yekai' and pass_word='0' or '1=1'   sql注入
	{
		printf("zhe yang bu hao!\n");
		return 0;
	}
	char rSql[512] = { 0 };
	sprintf(rSql, "select user_id from t_user_info where user_id='%s' and pass_word='%s'", User, Passwd);
	if (mysql_query(mysql, rSql) != 0) 
	{
		printf("mysql exe err: %s\n", rSql);
		return -1;
	}
	MYSQL_RES* result = mysql_store_result(mysql); // 取结果集
	if (result != NULL)
	{
		int ret = (int)result->row_count;
		mysql_free_result(result);
		return ret;
	}
	return 0;
}

int CMysql::ListFileInfo(const char* User)
{
	// select * from t_file_info where user_id='yekai';
	char rSql[512] = { 0 };
	sprintf(rSql, "select * from t_file_info where user_id='%s'", User);
	if (mysql_query(mysql, rSql) != 0)
	{
		printf("mysql exe err: %s\n", rSql);
		return -1;
	}
	MYSQL_RES* result = mysql_store_result(mysql); // 取结果集
	if (result != NULL)
	{
		MYSQL_ROW row;
		unsigned int num_fields;
		unsigned int i;

		num_fields = mysql_num_fields(result);
		while ((row = mysql_fetch_row(result)))
		{
			unsigned long* lengths;
			lengths = mysql_fetch_lengths(result);
			for (i = 0; i < num_fields; i++)
			{
				printf("%s\t", row[i] ? row[i] : "NULL");
			}
			printf("\n");
		}
		mysql_free_result(result);
	}
	return 0;
}

int CMysql::UploadFile(const char* User, const char* LocalFile, const char* MongoFile)
{
	// insert into t_file_info(local_file_name, mongo_file_name, file_size, user_id, status, remark)
	// values('xxx.11', 'yyy.11', 1024, 'yekai', '0', 'upload success');
	char rSql[512] = { 0 };
	sprintf(rSql, "insert into t_file_info(local_file_name, mongo_file_name, file_size, user_id, status, remark)\
					values('%s', '%s', 0, '%s', '0', 'uploading')", LocalFile, MongoFile, User);
	if (mysql_query(mysql, rSql) != 0)
	{
		printf("run upload err: %s\n", rSql);
		return -1;
	}
	return 0;
}

int CMysql::UpdateFileInfo(int FileSize, const char* User, const char* LocalFile, const char* MongoFile)
{
	// update t_file_info set file_size=1011, status='1', remark='upload success' where user_id='yekai' and local_file_name='xxx.11' and mongo_file_name='yyy.11'
	char rSql[512] = { 0 };
	sprintf(rSql, "update t_file_info set file_size=%d, status='1', remark='upload success' where user_id='%s' \
			and local_file_name='%s' and mongo_file_name='%s'", FileSize, User, LocalFile, MongoFile);
	if (mysql_query(mysql, rSql) != 0)
	{
		printf("run update err: %s\n", rSql);
		return -1;
	}
	return 0;
}

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// CMongo.h
#pragma once
#include <iostream>

class CMongo
{
public:
	CMongo();
	size_t UploadFile(const char* LocalFile, const char* MongoFile);
	int DownloadFile(const char* MongoFile, const char* DesFile);
	~CMongo();
};
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// CMongo.cpp
#include "CMongo.h"
#include <bsoncxx/builder/basic/document.hpp>
#include <bsoncxx/json.hpp>
#include <mongocxx/client.hpp>
#include <mongocxx/instance.hpp>
#include <mongocxx/stdx.hpp>
#include <mongocxx/uri.hpp>
#include <fstream>

using bsoncxx::builder::basic::kvp;
using bsoncxx::builder::basic::make_array;
using bsoncxx::builder::basic::make_document;

mongocxx::instance instance{};  // Required to initialize the driver
mongocxx::client client{ mongocxx::uri{ "mongodb://localhost:27017" } };
//mongocxx::database db = client["ods"];
mongocxx::gridfs::bucket bucket = client["ods"].gridfs_bucket();

CMongo::CMongo()
{
    // 检查连接是否成功
    auto databases = client.list_databases();
    if (databases.begin() == databases.end()) 
    {
        std::cout << "Failed to connect to MongoDB server." << std::endl;
        exit(1);
    }
}

CMongo::~CMongo()
{

}

size_t CMongo::UploadFile(const char* LocalFile, const char* MongoFile)
{
    std::ifstream file(LocalFile, std::ios::in | std::ios::binary);
    if (!file) {
        throw std::runtime_error{ "unable to open file: " + std::string(LocalFile) };
    }

    mongocxx::gridfs::uploader uploader = bucket.open_upload_stream(MongoFile);
    const int buffer_size = 40960;
    char buffer[buffer_size];
    size_t fileSize = 0;
    while (!file.eof())
    {
        file.read(buffer, buffer_size);
        std::streamsize bytesRead = file.gcount();
        uploader.write(reinterpret_cast<uint8_t*>(buffer), bytesRead);
        fileSize += (size_t)bytesRead;
    }
    auto result = uploader.close();
    if (result.id().type() == bsoncxx::type::k_oid) {
        // 文件上传成功，可以获取文件的唯一ID
        auto fileId = result.id().get_oid().value.to_string();
        std::cout << "文件上传成功，文件ID：" << fileId << std::endl;
    }
    file.close();
    return fileSize;
}

int CMongo::DownloadFile(const char* MongoFile, const char* DesFile) {
    bsoncxx::document::value filter = make_document(kvp("filename", MongoFile));
    mongocxx::cursor cursor = bucket.find(filter.view());
    if (cursor.begin() != cursor.end())
    {
        std::ofstream file(DesFile, std::ios::out | std::ios::binary);
        bsoncxx::document::view documentView = *cursor.begin();
        bsoncxx::types::bson_value::view id = documentView["_id"].get_value();
        auto downloader = bucket.open_download_stream(id);
        const int buffer_size = 4096;
        char buffer[buffer_size];
        size_t readbyte = 0;
        while ((readbyte = downloader.read((uint8_t*)buffer, buffer_size)) != 0)
        {
            file.write(buffer, readbyte);
        }
        file.close();
        downloader.close();
    }
    else
    {
        return -1;
    }
    return 0;  // 返回0表示下载成功
}
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// main.cpp
#include<iostream>
#include<vector>
#include<string>

#include "CMysql.h"
#include "CMongo.h"

using namespace std;

void splitString(const char* Src, char delim, vector<string>& vsplit)
{
	string tmp = Src;
	vsplit.clear();
	int index = 0;
	size_t last = 0;
	last = tmp.find_first_not_of(delim, last); // 找到第一个不为分隔符的字符
	index = tmp.find_first_of(delim, last); //找到第一个分隔符
	while (index != string::npos) // npos代表字符串的结尾
	{
		vsplit.push_back(tmp.substr(last, index - last));
		last = tmp.find_first_not_of(delim, index);
		index = tmp.find_first_of(delim, last);
	}
	if (index == string::npos && tmp.length() > last)//到末尾了,如果整个长度大于last坐标,说明还有最后一个字符要放到vector
	{
		vsplit.push_back(tmp.substr(last));
	}
#if 0
	cout << vsplit.size() << endl;
	for (size_t i = 0; i < vsplit.size(); i++)
	{
		cout << "i=" << i << "," << vsplit[i].c_str() << endl;
	}
#endif
}

int main(int argc, char* argv[])
{
	system("stty erase ^H");  // 解决backspace键显示^H问题
	if (argc != 3)
	{
		cout << "./main user passwd" << endl;
		return -1;
	}
	vector<string> vCmd;
	string line;
	CMysql cmysql;
	CMongo cmongo;
	if (cmysql.UserLogin(argv[1], argv[2]) < 1)
	{
		cout << "login err" << endl;
		return -1;
	}
	while (1)
	{
		cout << "ods> ";
		getline(cin, line);
		splitString(line.c_str(), ' ', vCmd);
		if (vCmd.empty()) continue;
		if (vCmd[0].compare("quit") == 0) // quit
		{
			cout << "bye bye!" << endl;
			break;
		}
		else if (vCmd[0].compare("upload") == 0)
		{
			cout << "upload" << vCmd[1] << ", " << vCmd[2] << endl;
			cmysql.UploadFile(argv[1], vCmd[1].c_str(), vCmd[2].c_str());
			size_t size = cmongo.UploadFile(vCmd[1].c_str(), vCmd[2].c_str());
			cmysql.UpdateFileInfo(size, argv[1], vCmd[1].c_str(), vCmd[2].c_str());
		}
		else if (vCmd[0].compare("download") == 0)
		{
			cout << "download" << vCmd[1] << ", " << vCmd[2] << endl;
			if (cmongo.DownloadFile(vCmd[1].c_str(), vCmd[2].c_str()) != 0)
			{
				cout << "文件未找到" << endl;
			}
		}
		else if (vCmd[0].compare("list") == 0)
		{
			// cout << "list" << endl;
			cmysql.ListFileInfo(argv[1]);
		}
	}
	return 0;
}

编译指令： 注意GCC的版本

1
g++ main.cpp CMysql.cpp CMongo.cpp -o main -I/usr/include/mysql -L/usr/lib64/mysql -lmysqlclient -ldl -lpthread -lrt -I/usr/local/include/mongocxx/v_noabi -I/usr/local/include/bsoncxx/v_noabi  -L/usr/local/lib64 -lmongocxx -lbsoncxx

image-20230805182700262

image-20230805182804046

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