Q:

For spring project, Do i need to inject pagerequest object?

I read some articles conecerning clean architecture.
These articles say that business layer should not know how to solve domain knowledge directly. (only what to do)
PageRequest object is provided by spring framework.
And this object implements Pageable interface.
My question is...
Do i create the Pagerequest in business layer (service)
or inject it to the layer?

A:

You said the PageRequest / Pageable object is provided by Spring, so - if you are using Spring MVC - I would expect something like the following on controller level:
@RequestMapping(method = ..., path = ..., produces = ...)
public ... readSomethingPaged(@PathVariable String ..., Pageable pageable) {
   ...
}

Then of course you have to pass this Pageable (created automagically by Spring using the request parameters page=...&size=...&sort=...) through your service layer down to the place you are getting the data from. Within Spring (Boot) a Spring Data JPA repository comes in handy. It accepts the Pageable created by the controller and returns the appropriate data.
Or what exactly do you mean with "Do i create the Pagerequest in business layer"?
If you really have to create your own PageRequest it has to be done before the repository is called, then imho not the service itself but the controller / a facade should be responsible for that. 

