ProtocolCommandEvent.java

/*
 * 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.commons.net;

import java.util.EventObject;

/**
 * There exists a large class of IETF protocols that work by sending an ASCII text command and arguments to a server, and then receiving an ASCII text reply.
 * For debugging and other purposes, it is extremely useful to log or keep track of the contents of the protocol messages. The ProtocolCommandEvent class
 * coupled with the {@link org.apache.commons.net.ProtocolCommandListener} interface facilitate this process.
 *
 *
 * @see ProtocolCommandListener
 * @see ProtocolCommandSupport
 */

public class ProtocolCommandEvent extends EventObject {
    private static final long serialVersionUID = 403743538418947240L;

    private final int replyCode;
    private final boolean isCommand;
    private final String message, command;

    /**
     * Creates a ProtocolCommandEvent signalling a reply to a command was received. ProtocolCommandEvents created with this constructor should only be sent
     * after a complete command reply has been received from a server.
     *
     * @param source    The source of the event.
     * @param replyCode The integer code indicating the natureof the reply. This will be the protocol integer value for protocols that use integer reply codes,
     *                  or the reply class constant corresponding to the reply for protocols like POP3 that use strings like OK rather than integer codes (i.e.,
     *                  POP3Repy.OK).
     * @param message   The entire reply as received from the server.
     */
    public ProtocolCommandEvent(final Object source, final int replyCode, final String message) {
        super(source);
        this.replyCode = replyCode;
        this.message = message;
        this.isCommand = false;
        this.command = null;
    }

    /**
     * Creates a ProtocolCommandEvent signalling a command was sent to the server. ProtocolCommandEvents created with this constructor should only be sent after
     * a command has been sent, but before the reply has been received.
     *
     * @param source  The source of the event.
     * @param command The string representation of the command type sent, not including the arguments (e.g., "STAT" or "GET").
     * @param message The entire command string verbatim as sent to the server, including all arguments.
     */
    public ProtocolCommandEvent(final Object source, final String command, final String message) {
        super(source);
        this.replyCode = 0;
        this.message = message;
        this.isCommand = true;
        this.command = command;
    }

    /**
     * Returns the string representation of the command type sent (e.g., "STAT" or "GET"). If the ProtocolCommandEvent is a reply event, then null is returned.
     *
     * @return The string representation of the command type sent, or null if this is a reply event.
     */
    public String getCommand() {
        return command;
    }

    /**
     * Returns the entire message sent to or received from the server. Includes the line terminator.
     *
     * @return The entire message sent to or received from the server.
     */
    public String getMessage() {
        return message;
    }

    /**
     * Returns the reply code of the received server reply. Undefined if this is not a reply event.
     *
     * @return The reply code of the received server reply. Undefined if not a reply event.
     */
    public int getReplyCode() {
        return replyCode;
    }

    /**
     * Returns true if the ProtocolCommandEvent was generated as a result of sending a command.
     *
     * @return true If the ProtocolCommandEvent was generated as a result of sending a command. False otherwise.
     */
    public boolean isCommand() {
        return isCommand;
    }

    /**
     * Returns true if the ProtocolCommandEvent was generated as a result of receiving a reply.
     *
     * @return true If the ProtocolCommandEvent was generated as a result of receiving a reply. False otherwise.
     */
    public boolean isReply() {
        return !isCommand();
    }
}