The following exception can occur when using ProxySelector.getDefault();

        ProxySelector ps = ProxySelector.getDefault();
        HttpClient client = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_1_1)
            .proxy(ps)
            .build();
        HttpRequest request = HttpRequest.newBuilder()
            .GET()
            .uri(new URI("https://www.oracle.com/"))
            .build();

        HttpResponse<String> response
            = client.send(request, HttpResponse.BodyHandler.asString());
        System.out.println(response.body());


Exception in thread "main" java.nio.channels.UnresolvedAddressException
at java.base/sun.nio.ch.Net.checkAddress(Net.java:112)
at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:622)
at jdk.incubator.httpclient/jdk.incubator.http.PlainHttpConnection.connect(PlainHttpConnection.java:151)
at jdk.incubator.httpclient/jdk.incubator.http.PlainTunnelingConnection.connect(PlainTunnelingConnection.java:74)
at jdk.incubator.httpclient/jdk.incubator.http.SSLTunnelConnection.connect(SSLTunnelConnection.java:53)
at jdk.incubator.httpclient/jdk.incubator.http.Http1Exchange.sendHeadersOnly(Http1Exchange.java:134)
at jdk.incubator.httpclient/jdk.incubator.http.Exchange.responseImpl0(Exchange.java:297)
at jdk.incubator.httpclient/jdk.incubator.http.Exchange.responseImpl(Exchange.java:245)
at jdk.incubator.httpclient/jdk.incubator.http.Exchange.response(Exchange.java:121)
at jdk.incubator.httpclient/jdk.incubator.http.MultiExchange.response(MultiExchange.java:154)
at jdk.incubator.httpclient/jdk.incubator.http.HttpClientImpl.send(HttpClientImpl.java:234)