Do not override resolve method (#1000)

* Do not override resolve method

* Just one IP is enough

Author: tomas-sexenian

java/src/main/java/com/genexus/internet/HttpClientJavaLib.java

@@ -66,45 +66,35 @@
 
 public class HttpClientJavaLib extends GXHttpClient {
 
-	private static class FirstIpDnsResolver implements DnsResolver {
-		private final DnsResolver defaultDnsResolver = new SystemDefaultDnsResolver();
-
-		@Override
-		public InetAddress[] resolve(final String host) throws UnknownHostException {
-			InetAddress[] allIps = defaultDnsResolver.resolve(host);
-			if (allIps != null && allIps.length > 0) {
-				return new InetAddress[]{allIps[0]};
-			}
-			return allIps;
+	private static final DnsResolver FIRST_IP_DNS_RESOLVER = host -> {
+		InetAddress[] allIps = SystemDefaultDnsResolver.INSTANCE.resolve(host);
+		if (allIps != null && allIps.length > 0) {
+			return new InetAddress[]{allIps[0]};
 		}
-	}
+		return allIps;
+	};
 
-	private static String getGxIpResolverConfig() {
+	private static boolean isFirstIpDnsEnabled() {
 		String name = "GX_USE_FIRST_IP_DNS";
 		String gxDns = System.getProperty(name);
 		if (gxDns == null || gxDns.trim().isEmpty()) {
 			gxDns = System.getenv(name);
 		}
-		if (gxDns != null && gxDns.trim().equalsIgnoreCase("true")) {
-			return gxDns.trim();
-		} else {
-			return null;
-		}
+		return gxDns != null && gxDns.trim().equalsIgnoreCase("true");
 	}
 
-
 	public HttpClientJavaLib() {
 		getPoolInstance();
 		ConnectionKeepAliveStrategy myStrategy = generateKeepAliveStrategy();
 		HttpClientBuilder builder = HttpClients.custom()
 			.setConnectionManager(connManager)
 			.setConnectionManagerShared(true)
 			.setKeepAliveStrategy(myStrategy);
-		if (getGxIpResolverConfig() != null) {
-			builder.setDnsResolver(new FirstIpDnsResolver());
+		if (isFirstIpDnsEnabled()) {
+			builder.setDnsResolver(FIRST_IP_DNS_RESOLVER);
 		}
 		httpClientBuilder = builder;
-		cookies = new BasicCookieStore();		
+		cookies = new BasicCookieStore();
 		streamsToClose = new Vector<>();
 	}
 
@@ -114,10 +104,11 @@ private static void getPoolInstance() {
 				RegistryBuilder.<ConnectionSocketFactory>create()
 					.register("http", PlainConnectionSocketFactory.INSTANCE).register("https", getSSLSecureInstance())
 					.build();
-			boolean useCustomDnsResolver = getGxIpResolverConfig() != null;
-			PoolingHttpClientConnectionManager connManager = useCustomDnsResolver
-				? new PoolingHttpClientConnectionManager(socketFactoryRegistry, new FirstIpDnsResolver())
-				: new PoolingHttpClientConnectionManager(socketFactoryRegistry);
+			if (isFirstIpDnsEnabled()) {
+				connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry, FIRST_IP_DNS_RESOLVER);
+			} else {
+				connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
+			}
 			connManager.setMaxTotal((int) CommonUtil.val(clientCfg.getProperty("Client", "HTTPCLIENT_MAX_SIZE", "1000")));
 			connManager.setDefaultMaxPerRoute((int) CommonUtil.val(clientCfg.getProperty("Client", "HTTPCLIENT_MAX_PER_ROUTE", "1000")));
 
@@ -675,7 +666,7 @@ public void execute(String method, String url) {
 			resetStateAdapted();
 		}
 	}
-	
+
 	private synchronized void displayHTTPConnections(){
 		Iterator<HttpRoute> iterator = storedRoutes.iterator();
 		while (iterator.hasNext()) {