When i read document on the internet, sometime i see the phase "on the fly". Ex: "In a typical Java application, you’d expect to write a class that implements CustomerRepository. But that’s what makes Spring Data JPA so powerful: You don’t have to write an implementation of the repository interface. Spring Data JPA creates an implementation on the fly when you run the application." i dont understand what is mean?
Some one tell me please? So thanks. i m from Viet Nam, so my english is not good!!
In this context, on the fly means while the application is running. That is, at run-time, not compile-time.
In your example, "on the fly" means "while the program is running". While the program is running, it creates an implementation of the interface. At runtime, not compile-time.
Let me give you another example, when you write a java swing program, sometimes you need to add some components to the JFrame when the user presses a button or something. You want to create the components by hand, not by the designer. You can say that you create components and add them to the JFrame on the fly.
