非标准端口上的HTTP/HTTPS连接，实现灵活端口出口

package com.adobe.aem.wknd.examples.core.connections.impl;

import com.adobe.aem.wknd.examples.core.connections.ExternalService;
import org.osgi.service.component.annotations.Component;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ProxySelector;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;

@Component
public class HttpExternalServiceImpl implements ExternalService {
    private static final Logger log = LoggerFactory.getLogger(HttpExternalServiceImpl.class);

    @Override
    public boolean isAccessible() {
        HttpClient client;

        // Use System.getenv("AEM_PROXY_HOST") and proxy port System.getenv("AEM_HTTP_PROXY_PORT")
        // or System.getenv("AEM_HTTPS_PROXY_PORT"), depending on if the destination requires HTTP/HTTPS

        if (System.getenv("AEM_PROXY_HOST") != null) {
            // Create a ProxySelector that uses to AEM's provided AEM_PROXY_HOST, with a fallback of proxy.tunnel, and proxy port using the AEM_HTTP_PROXY_PORT variable.
            // If the destination requires HTTPS, then use the variable AEM_HTTPS_PROXY_PORT instead of AEM_HTTP_PROXY_PORT.

            ProxySelector proxySelector = ProxySelector.of(new InetSocketAddress(
                System.getenv().getOrDefault("AEM_PROXY_HOST", "proxy.tunnel"),
                Integer.parseInt(System.getenv().get("AEM_HTTP_PROXY_PORT"))));

            client = HttpClient.newBuilder().proxy(proxySelector).build();
            log.debug("Using HTTPClient with AEM_PROXY_HOST");
        } else {
            client = HttpClient.newBuilder().build();
            // If no proxy is set up (such as local dev)
            log.debug("Using HTTPClient without AEM_PROXY_HOST");
        }

        // Prepare the full URI to request, note this will have the
        // - Scheme (http/https)
        // - External host name
        // - External port
        // The external service URI, including the scheme/host/port, is defined in code, and NOT in Cloud Manager portForwards rules.
        URI uri = URI.create("http://api.example.com:8080/test.json");

        // Prepare the HttpRequest
        HttpRequest request = HttpRequest.newBuilder().uri(uri).timeout(Duration.ofSeconds(2)).build();

        // Send the HttpRequest using the configured HttpClient
        HttpResponse<String> response = null;
        try {
            // Request the URL
            response = client.send(request, HttpResponse.BodyHandlers.ofString());

            log.debug("HTTP response body: {} ", response.body());

            // Our simple example returns true is response is successful! (200 status code)
            return response.statusCode() == 200;
        } catch (IOException e) {
            return false;
        } catch (InterruptedException e) {
            return false;
        }
    }
}