public static HugeClient tryConnect()

in hugegraph-hubble/hubble-be/src/main/java/org/apache/hugegraph/util/HugeClientUtil.java [44:129]
83 lines of code
29 McCabe index (conditional complexity)

    public static HugeClient tryConnect(GraphConnection connection) {
        String graph = connection.getGraph();
        String host = connection.getHost();
        Integer port = connection.getPort();
        String username = connection.getUsername();
        String password = connection.getPassword();
        int timeout = connection.getTimeout();
        String protocol = connection.getProtocol() == null ?
                          DEFAULT_PROTOCOL : connection.getProtocol();
        String trustStoreFile = connection.getTrustStoreFile();
        String trustStorePassword = connection.getTrustStorePassword();

        String url = UriComponentsBuilder.newInstance()
                                         .scheme(protocol).host(host).port(port).toUriString();
        if (username == null) {
            username = "";
            password = "";
        }
        HugeClient client;
        try {
            client = HugeClient.builder(url, graph)
                               .configUser(username, password)
                               // TODO: change it to connTimeout & readTimeout
                               .configTimeout(timeout)
                               .configSSL(trustStoreFile, trustStorePassword)
                               .configHttpBuilder(http -> http.followRedirects(false))
                               .build();
        } catch (IllegalStateException e) {
            String message = e.getMessage();
            if (message != null && message.startsWith("The version")) {
                throw new ExternalException("client-server.version.unmatched", e);
            }
            if (message != null && (message.startsWith("Error loading trust store from") ||
                                    message.startsWith("Cannot find trust store file"))) {
                throw new ExternalException("https.load.truststore.error", e);
            }
            throw e;
        } catch (ServerException e) {
            String message = e.getMessage();
            if (Constant.STATUS_UNAUTHORIZED == e.status() ||
                (message != null && message.startsWith("Authentication"))) {
                throw new ExternalException("graph-connection.username-or-password.incorrect", e);
            }
            if (message != null && message.contains("Invalid syntax for username and password")) {
                throw new ExternalException("graph-connection.missing-username-password", e);
            }
            throw new GenericException(e);
        } catch (ClientException e) {
            Throwable cause = e.getCause();
            if (cause == null || cause.getMessage() == null) {
                throw e;
            }
            String message = cause.getMessage();
            if (message.contains("Connection refused")) {
                throw new ExternalException("service.unavailable", e, host, port);
            } else if (message.contains("java.net.UnknownHostException") ||
                       message.contains("Host name may not be null")) {
                throw new ExternalException("service.unknown-host", e, host);
            } else if (message.contains("<!doctype html>")) {
                throw new ExternalException("service.suspected-web", e, host, port);
            }
            throw e;
        } catch (Exception e) {
            throw new GenericException(e);
        }

        try {
            ResultSet rs = client.gremlin().gremlin("g.V().limit(1)").execute();
            rs.iterator().forEachRemaining(Result::getObject);
        } catch (ServerException e) {
            if (Constant.STATUS_UNAUTHORIZED == e.status()) {
                throw new ExternalException("graph-connection.username-or-password.incorrect", e);
            }
            String message = e.message();
            if (message != null && message.contains("Could not rebind [g]")) {
                throw new ExternalException("graph-connection.graph.unexist", e, graph, host, port);
            }
            if (!isAcceptable(message)) {
                throw e;
            }
        } catch (Exception e) {
            client.close();
            throw e;
        }
        return client;
    }