117笔记问答在C++中实现Oracle数据库连接池，可以使用Oracle官方提供的Oracle Call Interface (OCI) 库
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首先，确保已经安装了Oracle客户端库和OCI库。可以从Oracle官网下载并安装。
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包含必要的头文件：
#include#include #include #include #include
- 定义一个连接池类，如下所示：
class OracleConnectionPool {
public:
OracleConnectionPool(const std::string& connectionString, const std::string& userName, const std::string& password, int poolSize);
~OracleConnectionPool();
oracle::occi::Connection* getConnection();
void releaseConnection(oracle::occi::Connection* connection);
private:
std::vector connections_;
std::vector connectionStatus_;
std::mutex mutex_;
std::condition_variable cv_;
};
- 实现连接池类的构造函数、析构函数、获取连接和释放连接的方法：
OracleConnectionPool::OracleConnectionPool(const std::string& connectionString, const std::string& userName, const std::string& password, int poolSize) {
for (int i = 0; i< poolSize; ++i) {
oracle::occi::Environment* env = oracle::occi::Environment::createEnvironment(oracle::occi::Environment::DEFAULT);
oracle::occi::Connection* conn = env->createConnection(userName, password, connectionString);
connections_.push_back(conn);
connectionStatus_.push_back(true);
}
}
OracleConnectionPool::~OracleConnectionPool() {
for (auto conn : connections_) {
conn->close();
oracle::occi::Environment::terminateEnvironment(conn->getEnvironment());
}
}
oracle::occi::Connection* OracleConnectionPool::getConnection() {
std::unique_lock lock(mutex_);
cv_.wait(lock, [this] { return std::any_of(connectionStatus_.begin(), connectionStatus_.end(), [](bool status) { return status; }); });
auto it = std::find(connectionStatus_.begin(), connectionStatus_.end(), true);
size_t index = std::distance(connectionStatus_.begin(), it);
connectionStatus_[index] = false;
return connections_[index];
}
void OracleConnectionPool::releaseConnection(oracle::occi::Connection* connection) {
std::unique_lock lock(mutex_);
auto it = std::find(connections_.begin(), connections_.end(), connection);
size_t index = std::distance(connections_.begin(), it);
connectionStatus_[index] = true;
cv_.notify_one();
}
- 使用连接池：
int main() {
OracleConnectionPool pool("localhost:1521/XE", "username", "password", 5);
oracle::occi::Connection* conn = pool.getConnection();
oracle::occi::Statement* stmt = conn->createStatement("SELECT * FROM your_table");
oracle::occi::ResultSet* rs = stmt->executeQuery();
while (rs->next()) {
// 处理查询结果
}
stmt->closeResultSet(rs);
conn->terminateStatement(stmt);
pool.releaseConnection(conn);
return 0;
}
这样就实现了一个简单的Oracle数据库连接池。请注意，这个实现仅作为示例，实际应用中可能需要根据需求进行调整和优化。