Micrometer metrics exporter for apache http connection pool

gistfile1.txt

1. Create a scheduler to add new routes
@Scheduled(fixedRate = 300000)
    public void updateHttpRoutes() {
        Set<HttpRoute> routes = poolingHttpClientConnectionManager.getRoutes();
        for (HttpRoute route : routes) {
            httpMetricsTracker.add(route, poolingHttpClientConnectionManager);
        }
    }