Trying to stop all other running threads with CompletableFuture

Question

i'm trying to run a for loop on parrallel using 4 threads and I have to stop all other threads when it gets to an else, basically the code looks like this:

CompletableFuture<ResponseEntity<TramRealTimeResponse>> responseEntityCompletableFuture = null;
        ExecutorService pool = Executors.newFixedThreadPool(4);

        for (TramRulesDTO rule : tramRulesResponse.getPayload()) {
            responseEntityCompletableFuture = CompletableFuture.supplyAsync(() ->
            {
                logger.info("thread " + Thread.currentThread().getName());

                TramRule tramRule = TramRuleFactory.getTramRule(rule.getRuleId());
                PartnerRuleDto partnerRuleDto = getPartnerRule(partnerRuleResponse.getPayload(), rule.getRuleId());

                if (Objects.nonNull(tramRule)) {
                    try {
                        
                        tramRule.doTramLogicAndReturnAction(rule, partnerRuleDto,
                                paymentDetails, intermediaryDetails, partnerRulesConditions, tramRulesRequest);
                    } catch (TramRealTimeException ex) {
                        TramRealTimeResponse response = exceptionHandler.handleTramRealTimeException(ex, partnerRuleDto);
                        if (response.getStatus().equals(200)) {
                            return null;
                        } else {
                            //Stop all threads
                            return ResponseEntity.ok(response);
                        }
                    }

                } else {
                    return null;
                }
                return null;
            }, pool);
        }
        ResponseEntity<TramRealTimeResponse> tramRealTimeResponseResponseEntity = responseEntityCompletableFuture.get();

Where is the //Stop all threads comment I need somehow to stop all other threads and retrieve the ResponseEntity object down after the for loop. I've tried with executor service shutDown() and shutDownAll() and it doesn't stop anything