Java tutorial
/**************************************************************** * Licensed to the Apache Software Foundation (ASF) under one * * or more contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The ASF licenses this file * * to you under the Apache License, Version 2.0 (the * * "License"); you may not use this file except in compliance * * with the License. You may obtain a copy of the License at * * * * http://www.apache.org/licenses/LICENSE-2.0 * * * * Unless required by applicable law or agreed to in writing, * * software distributed under the License is distributed on an * * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * * KIND, either express or implied. See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/ package org.apache.james.smtpserver.fastfail; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import javax.inject.Inject; import org.apache.commons.configuration.Configuration; import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.HierarchicalConfiguration; import org.apache.james.dnsservice.api.DNSService; import org.apache.james.protocols.api.handler.ProtocolHandler; public class DNSRBLHandler extends org.apache.james.protocols.smtp.core.fastfail.DNSRBLHandler implements ProtocolHandler { private DNSService dns; @Inject public void setDNSService(DNSService dns) { this.dns = dns; } @Override public void init(Configuration config) throws ConfigurationException { boolean validConfig = false; HierarchicalConfiguration handlerConfiguration = (HierarchicalConfiguration) config; ArrayList<String> rblserverCollection = new ArrayList<String>(); Collections.addAll(rblserverCollection, handlerConfiguration.getStringArray("rblservers.whitelist")); if (rblserverCollection.size() > 0) { setWhitelist(rblserverCollection.toArray(new String[rblserverCollection.size()])); rblserverCollection.clear(); validConfig = true; } Collections.addAll(rblserverCollection, handlerConfiguration.getStringArray("rblservers.blacklist")); if (rblserverCollection.size() > 0) { setBlacklist(rblserverCollection.toArray(new String[rblserverCollection.size()])); rblserverCollection.clear(); validConfig = true; } // Throw an ConfiigurationException on invalid config if (!validConfig) { throw new ConfigurationException("Please configure whitelist or blacklist"); } setGetDetail(handlerConfiguration.getBoolean("getDetail", false)); } @Override public void destroy() { // Do nothing } @Override protected boolean resolve(String ip) { try { dns.getByName(ip); return true; } catch (UnknownHostException e) { return false; } } @Override protected Collection<String> resolveTXTRecords(String ip) { return dns.findTXTRecords(ip); } }