试图修复我编译的jar中的错误

Question

我编制了我的jar并获得了以下内容：

    java.io.FileNotFoundException: Employees\firstname lastname.txt (The system cannot find the path specified)
    Exception in thread "main" java.lang.NullPointerException
    at EmployeeList.createEmployees(EmployeeList.java:127)
    at EmployeesWindow.<init>(EmployeesWindow.java:64)
    at ScheduleBuilder.<init>(ScheduleBuilder.java:17)
    at Start.main(Start.java:7)

我的文件路径如下：

    File file = new File("Employees\\" + tempfirst + " " + templast + ".txt");

该文件夹位于此处，包含一堆员工文本文件：

    F:\Programming\Schedule Builder\Employees

如何解决这个问题，以免我收到此错误？