Spring REST templates - difference between put() and exchange() -

this test case writing update calls database:

@test public void testupdatelist() {     //     //... variables     //     httpheaders headers = new httpheaders();     headers.setcontenttype(mediatype.application_json);      string requestbody = "{\"id\":\"" + givenid + "\",\"listname\":\"" + listname + "\",\"owner\":\"" + owner + "\"}";      httpentity <string> entity = new httpentity<>(requestbody, headers);      // call update     responseentity <tasklistresponse> list = template.exchange(request_url + "/list/update/{id}", httpmethod.put, entity, tasklistresponse.class, params); } 

here params name-value hashmap rest url.

when wanted update list type, since resttemplate.put() doesn't have return type, used http requests. call template.put this:

   template.put(request_url + "/list/update/{id}", request, params); 

• but don't know difference between 2 types of calls. explain me in reference above code? how can template.exchange return value, if it's put request?

• what i'm looking since used template.post/get/delete create(), search() , delete(), should use .put() update() well, though won't response?