Ich verwende die HttpURLConnection-Klasse, um eine Verbindung zu einem externen Webdienst von Eclipse herzustellen. Dann wird die Fehlermeldung "Connection Refused" (Verbindung abgelehnt) angezeigt.

public class TestConnection {


    static {
        //for localhost testing only
        javax.net.ssl.HttpsURLConnection.setDefaultHostnameVerifier(
            new javax.net.ssl.HostnameVerifier(){

                    public boolean verify(String hostname,
                                      javax.net.ssl.SSLSession sslSession) {
                        if (hostname.equals("localhost")) {
                            return true;
                        }
                        return false;
                    }
                });
    }

    public static void main(String[] args)
    {




    HttpURLConnection urlConnection;
    try {
        //https get method with required parameters
    //  XMLHttpRequest s1 = new XMLHttpRequest ();
        urlConnection = (HttpURLConnection) ((new URL("https://google.com").openConnection()));
        urlConnection.setRequestMethod("GET");
        urlConnection.setRequestProperty("User-Agent", "");
        int HTTPS_RESPONSE_CODE = urlConnection.getResponseCode();

        BufferedReader in = new BufferedReader(
                new InputStreamReader(urlConnection.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        String HTTPS_RESULT=response.toString(); 
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    }

}

java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.connect(Unknown Source)
    at sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source)
    at sun.net.NetworkClient.doConnect(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
    at TestConnection.main(TestConnection.java:19)

Aber wenn ich versuche, über einen Browser eine Verbindung zu derselben Site herzustellen, kann ich eine Antwort vom Dienst erhalten. Können Sie mir bitte mitteilen, ob es eine Lösung gibt?