Spring-boot REST API print caller Address - spring-boot

Question

I am trying to print the IP address of the requester of my web service.
I am a beginner with spring-boot, and I am not sure which class to import or variable to use to print the caller IP and port number.
This is my controller class :
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;//added
import org.springframework.web.bind.annotation.RequestParam;//added
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.sql.*;
//Controller
#RestController
public class MyController {
#GetMapping(path = "/print-caller-address")
public String CallerAddress() {
return "Caller IP or Port Number";
}
}
I am using spring-boot-starter-web and spring-boot-starter-data-jpa as dependencies.
Many thanks.

Answer 1

Try this:
#RestController
public class MyController {
#GetMapping(path = "/print-caller-address")
public String getCallerAddress(HttpServletRequest request) {
return request.getRemoteAddr();
}
}
https://docs.oracle.com/javaee/6/api/javax/servlet/ServletRequest.html#getRemoteAddr()
Returns the Internet Protocol (IP) address of the client or last proxy
that sent the request.
If the request has gone through a proxy before hitting your REST server then you would need to look at the headers. The proxy will typically set a header idientifyign the originating IP, address as detailed below:
https://en.wikipedia.org/wiki/X-Forwarded-For
so you can use request.getHeader("X-Forwarded-For") to get the originating IP address. To catch all scenarios:
#RestController
public class MyController {
#GetMapping(path = "/print-caller-address")
public String getCallerAddress(HttpServletRequest request) {
if(request.getHeader("X-Forwarded-For") != null){
return request.getHeader("X-Forwarded-For")
}else{
return request.getRemoteAddr();
}
}
}

Answer 2

The solution is
#GetMapping(path = "/print-caller-address")
public String CallerAddress(HttpServletRequest request) {
return request.getRemoteAddr();
}
Add HttpServletRequest request to your method definition and then use the Servlet API
Spring Documentation here said in
15.3.2.3 Supported handler method arguments and return types
Handler methods that are annotated with #RequestMapping can have very flexible signatures.
Most of them can be used in arbitrary order (see below for more details).
Request or response objects (Servlet API). Choose any specific request or response type,
for example ServletRequest or HttpServletRequest