"optimization": {
	  "scripts": true,
	  "styles": {
		"minify": true,
		"inlineCritical": false
	  },
	  "fonts": true
	}

{
  "/rest": {
    "target": "https://localhost:9000",
    "changeOrigin": true,
    "secure": false,
    "logLevel": "debug",
    "timeout": 3600000
  }
}

****************************************************************************************
This is a simple server for use in testing or debugging Angular applications locally.
It hasn't been reviewed for security issues.

DON'T USE IT FOR PRODUCTION!
****************************************************************************************

works: curl 'http://localhost:4200/rest/events' -H 'Accept: text/event-stream' -H 'Connection: keep-alive' -H 'Pragma: no-cache' -H 'Cache-Control: no-cache'
fails: curl 'http://localhost:4200/rest/events' -H 'Accept: text/event-stream' --compressed -H 'Connection: keep-alive' -H 'Pragma: no-cache' -H 'Cache-Control: no-cache'

package com.example;

import java.io.IOException;
import java.time.Duration;
import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

import de.ehex.connector.basic.event.EventService;
import de.ehex.connector.mgmt.rest.RestConstants;

@Controller
@PreAuthorize(RestConstants.AUTH_ANY_ADMIN)
@RequestMapping(RestConstants.ANWENDUNGS_KONNEKTOR_BASEURL + "/ereignisse")
public class SseController {

  private static final Logger LOG = LoggerFactory.getLogger(SseController.class);

  private final CopyOnWriteArrayList<SseEmitter> emitters = new CopyOnWriteArrayList<>();

  @Autowired
  private EventService eventService;

  @Autowired
  private TaskScheduler scheduler;

  @PostConstruct
  public void init() {
    this.scheduler.scheduleAtFixedRate(this::sendTime, Instant.now(), Duration.ofSeconds(1));
  }

  @PreDestroy
  public void destroy() {
    try {
      this.emitters.forEach(e -> e.complete());
    } catch (final RuntimeException e) {
      this.emitters.clear();
    }
  }

  @RequestMapping(method = RequestMethod.GET, produces = { MediaType.TEXT_EVENT_STREAM_VALUE })
  public SseEmitter handle() {
    final SseEmitter emitter = new SseEmitter(600_000l);
    this.emitters.add(emitter);

    emitter.onCompletion(() -> {
      this.emitters.remove(emitter);
    });
    emitter.onTimeout(() -> {
      this.emitters.remove(emitter);
    });
    return emitter;
  }

  public void sendTime() {
    if (this.emitters.isEmpty()) {
      return;
    }

    String msg = Instant.now().toString();
    LOG.debug("sending msg to {} subscriber: {}", this.emitters.size(), msg);
    final List<SseEmitter> deadEmitters = new ArrayList<>();
    this.emitters.forEach(emitter -> {
      try {
        emitter.send(msg);
      } catch (final IOException e) {
        deadEmitters.add(emitter);
      }
    });

    this.emitters.removeAll(deadEmitters);
  }
}

     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 12.2.4
Node: 14.16.0
Package Manager: npm 6.14.11
OS: linux x64

Angular: 12.2.4
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1202.4
@angular-devkit/build-angular   12.2.4
@angular-devkit/core            12.2.4
@angular-devkit/schematics      12.2.4
@schematics/angular             12.2.4
rxjs                            6.6.3
typescript                      4.3.5