Need java design pattern suggestion for this case

In my case web application sends request object in REQ_OBJ1 format and expect response in RESP_OBJ1. With the help of REQOBJ1, I need to create EXT_REQ_OBJ1 which have some similar fields as REQOBJ1 and other fields need to be preprocessed. Once EXT_REQ_OBJ1 is ready, a URL will be called and gives response in EXT_RES_OBJ1.

Again EXT_RES_OBJ1 needs to be mapped with RESP_OBJ1.

Scenario is for apache camel route, where most of the route do these common tasks but logic remains different for all.

What should be design architecture to be followed here?