Java tutorial
/* * mxisd - Matrix Identity Server Daemon * Copyright (C) 2017 Maxime Dor * * https://max.kamax.io/ * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package io.kamax.mxisd.dns; import io.kamax.mxisd.config.DnsOverwriteConfig; import io.kamax.mxisd.exception.ConfigurationException; import io.kamax.mxisd.exception.InternalServerError; import org.apache.http.client.utils.URIBuilder; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import java.net.MalformedURLException; import java.net.URI; import java.net.URL; import java.util.HashMap; import java.util.Map; import static io.kamax.mxisd.config.DnsOverwriteConfig.Entry; @Component public class ClientDnsOverwrite { private Logger log = LoggerFactory.getLogger(ClientDnsOverwrite.class); private Map<String, Entry> mappings; @Autowired public ClientDnsOverwrite(DnsOverwriteConfig cfg) { mappings = new HashMap<>(); cfg.getHomeserver().getClient().forEach(e -> mappings.put(e.getName(), e)); } public URIBuilder transform(URI initial) { URIBuilder builder = new URIBuilder(initial); Entry mapping = mappings.get(initial.getHost()); if (mapping == null) { throw new InternalServerError("No DNS client override for " + initial.getHost()); } try { URL target = new URL(mapping.getValue()); builder.setScheme(target.getProtocol()); builder.setHost(target.getHost()); if (target.getPort() != -1) { builder.setPort(target.getPort()); } return builder; } catch (MalformedURLException e) { log.warn("Skipping DNS overwrite entry {} due to invalid value [{}]: {}", mapping.getName(), mapping.getValue(), e.getMessage()); throw new ConfigurationException( "Invalid DNS overwrite entry in homeserver client: " + mapping.getName(), e.getMessage()); } } }