SessionHandlerInterface::write

SessionHandlerInterface::write() is a method for writing session data to persistent storage. It is part of PHP's SessionHandlerInterface.

The method is defined as follows:

 SessionHandlerInterface::write(string $session_id, string $session_data): bool

Parameter description:

• $session_id: The unique identifier (session_id) representing the current session.
• $session_data: represents the data in the current session, passed in string.

Return value:

• Return true if session data is successfully written to persistent storage. Otherwise, return false.

Example usage:

 class MySessionHandler implements SessionHandlerInterface { public function write($session_id, $session_data) { // 将会话数据写入持久存储的逻辑实现// 假设将会话数据写入文件$file = '/path/to/sessions/' . $session_id; file_put_contents($file, $session_data); return true; } } // 设置自定义的会话处理程序$handler = new MySessionHandler(); session_set_save_handler($handler, true); // 启动会话session_start(); // 在会话中设置一些数据$_SESSION['user_id'] = 123; $_SESSION['username'] = 'john'; // 会话数据会在调用session_write_close() 时写入持久存储// 或在会话结束时自动写入持久存储// 手动调用session_write_close()，将会话数据写入持久存储session_write_close();

In the above example, we customize a session handler (MySessionHandler) and implement the write() method of the SessionHandlerInterface interface. In the write() method, we write the session data into a file. Then, we set the custom session handler to the handler of the current session through the session_set_save_handler() function. Finally, by calling the session_write_close() method, we manually write session data to the persistent storage.

Note that the write logic in the example is only an example, and in practice you may need to write session data to a database, a cache server, or other persistent storage.