simultaneously call multiple Api request in spring mvc - spring

Question

My requirement is, I have to call multiple API in my REST application . I want each API will work independently irrespective of waiting for response from the other. i.e I need if one API request take 5sec then all the api request should take 5sec also

Answer 1

You can make the API call inside a seperate thread as shown below:
new Thread(new Runnable() {
public void run() {
try {
// Do your api call here
}
catch(Exception e)
{// Log or do watever you need}
}
Thus the API call will work asynchronously !

Answer 2

You can use the org.springframework.web.client.AsyncRestTemplate class which return a ListenableFuture to get the value asynchronously. So your method will have take time equal to the most slowest api call.
public static void main(String[] args) {
AsyncRestTemplate asycTemp = new AsyncRestTemplate();
HttpMethod method = HttpMethod.GET;
// create request entity using HttpHeaders
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.TEXT_PLAIN);
HttpEntity<String> requestEntity = new HttpEntity<String>("params", headers);
ListenableFuture<ResponseEntity<String>> future = asycTemp.exchange("https://www.google.com", method, requestEntity, String.class);
ListenableFuture<ResponseEntity<String>> future1 = asycTemp.exchange("https://www.yahoo.com", method, requestEntity, String.class);
ListenableFuture<ResponseEntity<String>> future2 = asycTemp.exchange("https://www.bing.com", method, requestEntity, String.class);
try {
// waits for the result
ResponseEntity<String> entity = future.get();
// prints body source code for the given URL
System.out.println(entity.getBody());
entity = future1.get();
System.out.println(entity.getBody());
entity = future2.get();
System.out.println(entity.getBody());
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}