In the Spring3,How to call a another server's controller in my controller - spring

Question

I have 3 servers,serverA,serverB,serverC,Now in the serverC,some request from serverB is by processed,and then,I don't know what is the result(response),if it's resultA,I want give the resultA to the serverA as a request,else give the serverB.
so what I can do something in the serverC's controller,or there is something wrong in the desgin.
Please tell me what I should to do,Thanks.
This is my code.
serverA
#RestController
public class ControllerA {
#RequestMapping(value = "/methodA", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
public ResponseEntity<String> methodA(#RequestBody String something) {
// some process
return null;
}
serverB
#RestController
public class ControllerB {
#RequestMapping(value = "/methodB", consumes =MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<String> methodB(#RequestBody String something) {
// some process
return null;
}
serverC
#RestController
public class ControllerC {
public ResponseEntity<String> methodC(#RequestBody String someReq) {
if (checkPam(someReq)) {
**// I want to call the ControllerA in serverA.**
}else {
**// I want to call the ControllerB in serverB.**
}
return null;
}

Answer 1

You can simply Use RestTemplate:
#RestController
public class ControllerC {
public ResponseEntity<String> methodC(#RequestBody String someReq) {
RestTemplate restTemplate = new RestTemplate();
if (checkPam(someReq)) {
String fooResourceUrl
= "http://path-to-server-a/path-to-service-a";
ResponseEntity<String> response
= restTemplate.getForEntity(fooResourceUrl , String.class);
}else {
String fooResourceUrl
= "http://path-to-server-b/path-to-service-b";
ResponseEntity<String> response
= restTemplate.getForEntity(fooResourceUrl , String.class);
}
return null;
}
As you can see, I instantiate RestTemplate object by new operator, you can also declare RestTemplate bean in your context and then autowire it in your controller class.