protected FtpServer createServer() throws Exception {
assertTrue(USERS_FILE.getAbsolutePath() + " must exist", USERS_FILE
.exists());
DefaultFtpServerContext context = new DefaultFtpServerContext();
NioListener listener = new NioListener();
listener.setPort(port);
context.setListener("default", listener);
PropertiesUserManager userManager = new PropertiesUserManager();
userManager.setAdminName("admin");
userManager.setPasswordEncryptor(new ClearTextPasswordEncryptor());
userManager.setFile(USERS_FILE);
userManager.configure();
context.setUserManager(userManager);
return new FtpServer(context);
}