    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017
    018    package org.apache.commons.net.daytime;
    019
    020    import java.io.BufferedReader;
    021    import java.io.IOException;
    022    import java.io.InputStreamReader;
    023
    024    import org.apache.commons.net.SocketClient;
    025
    026    /***
    027     * The DaytimeTCPClient class is a TCP implementation of a client for the
    028     * Daytime protocol described in RFC 867.  To use the class, merely
    029     * establish a connection with
    030     * {@link org.apache.commons.net.SocketClient#connect  connect }
    031     * and call {@link #getTime  getTime() } to retrieve the daytime
    032     * string, then
    033     * call {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
    034     * to close the connection properly.
    035     * <p>
    036     * <p>
    037     * @author Daniel F. Savarese
    038     * @see DaytimeUDPClient
    039     ***/
    040
    041    public final class DaytimeTCPClient extends SocketClient
    042    {
    043        /*** The default daytime port.  It is set to 13 according to RFC 867. ***/
    044        public static final int DEFAULT_PORT = 13;
    045
    046        // Received dates will likely be less than 64 characters.
    047        // This is a temporary buffer used while receiving data.
    048        private final char[] __buffer = new char[64];
    049
    050        /***
    051         * The default DaytimeTCPClient constructor.  It merely sets the default
    052         * port to <code> DEFAULT_PORT </code>.
    053         ***/
    054        public DaytimeTCPClient ()
    055        {
    056            setDefaultPort(DEFAULT_PORT);
    057        }
    058
    059        /***
    060         * Retrieves the time string from the server and returns it.  The
    061         * server will have closed the connection at this point, so you should
    062         * call
    063         * {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
    064         * after calling this method.  To retrieve another time, you must
    065         * initiate another connection with
    066         * {@link org.apache.commons.net.SocketClient#connect  connect }
    067         * before calling <code> getTime() </code> again.
    068         * <p>
    069         * @return The time string retrieved from the server.
    070         * @exception IOException  If an error occurs while fetching the time string.
    071         ***/
    072        public String getTime() throws IOException
    073        {
    074            int read;
    075            StringBuilder result = new StringBuilder(__buffer.length);
    076            BufferedReader reader;
    077
    078            reader = new BufferedReader(new InputStreamReader(_input_));
    079
    080            while (true)
    081            {
    082                read = reader.read(__buffer, 0, __buffer.length);
    083                if (read <= 0)
    084                    break;
    085                result.append(__buffer, 0, read);
    086            }
    087
    088            return result.toString();
    089        }
    090
    091    }
    092