renderFile file download

Controller provides the renderFile series of methods to support file downloading. The default file download path is under the download subpath under the project root path, which is called the base file download path. You can set the file download base path through me.setBaseDownloadPath(baseDownloadPath) in the JFinalConfig.configConstant(Constants me) method. This path parameter accepts an absolute path starting with "/" or a windows disk drive letter, and you can point the base path to Outside the project root path, it is convenient for single-machine multi-instance deployment. When the path parameter is set to a relative path, it is a relative path based on the project root