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