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

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.

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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;
}

Check out the SO response here https://stackoverflow.com/questions/2047122/requestdispatcher-forward-vs-httpservletresponse-sendredirect — Karen12345, Jan 20 '18 at 09:07
by using classical HTTP response is always returned to the server who requests it. In your case also by using the `restTemplate` if serverB requests a resource, the response will always return to it. What you can do is to use some messaging system For example serverB makes a request. ServerC responds to it with http status code 200 (it means OK i accept your request) then it elaborates the request and by the request type it can generate a message (e.g. JMS, websocket etc..) on a topic/queue and the correct listener will intercept the message. Same for the second scenario to serverB — Angelo Immediata, Jan 20 '18 at 09:33

score 0 · Accepted Answer · answered Jan 20 '18 at 09:35

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.

Thanks for your words,I think it is great.But i get some new problem.In this case,Can I try call post something to methodC,but Mock the result that form serviceA or serviceB. — beike, Jan 22 '18 at 13:25
Your welcome, please ask a new question and explain your new situations. — saeid rastak, Feb 01 '18 at 07:12

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

1 Answers1