Java tutorial
/* * Licensed 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 com.ok2c.lightmtp.impl.protocol.cmd; import java.util.HashMap; import java.util.Locale; import java.util.Map; import org.apache.http.util.Args; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.ok2c.lightmtp.SMTPCode; import com.ok2c.lightmtp.SMTPCodes; import com.ok2c.lightmtp.SMTPCommand; import com.ok2c.lightmtp.SMTPErrorException; import com.ok2c.lightmtp.impl.protocol.ServerState; import com.ok2c.lightmtp.protocol.Action; import com.ok2c.lightmtp.protocol.CommandHandler; import com.ok2c.lightmtp.protocol.ProtocolHandler; public class DefaultProtocolHandler implements ProtocolHandler<ServerState> { private final Logger log = LoggerFactory.getLogger(getClass()); private final Map<String, CommandHandler<ServerState>> map; public DefaultProtocolHandler() { super(); this.map = new HashMap<String, CommandHandler<ServerState>>(); } public void register(final String cmd, final CommandHandler<ServerState> handler) { Args.notNull(cmd, "Command name"); Args.notNull(handler, "Command handler"); this.map.put(cmd.toUpperCase(Locale.US), handler); } public void unregister(final String cmd) { Args.notNull(cmd, "Command name"); this.map.remove(cmd.toUpperCase(Locale.US)); } @Override public Action<ServerState> handle(final SMTPCommand command) throws SMTPErrorException { Args.notNull(command, "Command"); String cmd = command.getVerb(); CommandHandler<ServerState> handler = this.map.get(cmd.toUpperCase(Locale.US)); if (handler != null) { if (this.log.isDebugEnabled()) { this.log.debug("Command " + command); } return handler.handle(command.getArgument(), command.getParams()); } else { throw new SMTPErrorException(SMTPCodes.ERR_PERM_SYNTAX_ERR_COMMAND, new SMTPCode(5, 5, 1), "command not recognized"); } } }