How to structure spring controllers with functionality shared between web pages

Question

What's a good way to structure spring web controllers when there are different web pages that share functionality?

Let's say there are a Tasks and a Task web page. I can start a task from both pages and I expect that I will remain on the same page when doing so .

What's the best way to do this? Am i forced to duplicate logic as follows:

@Controller
@RequestMapping("/tasks")
public class TasksController {

    @GetMapping("/{id}/start")
    public String start(@PathVariable String id) {
        tasks.start(id);
        return "redirect:/tasks.html";
    }
}

and

@Controller
@RequestMapping("/task")
public class TaskController {

    @GetMapping("/{id}/start")
    public String start(@PathVariable String id) {
        tasks.start(id);
        return "redirect:/task.html";
    }
}

ps. I'm not interested in async JavaScipt solutions.

Answer 1

You could use the Regex feature in path variables and get the page name in another variable. So, I would solve this the following way:

@Controller
public class TaskController {

    ...

    @GetMapping({"/{page:tasks?}/{id}/start")
    public String start(@PathVariable String page, @PathVariable String id) {
        tasks.start(id);
        return "redirect:/" + page + ".html";
    }
}

If there's more logic or the entry points are quite different extract the common code to a service.