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
018package org.apache.commons.net.daytime;
019
020import java.io.BufferedReader;
021import java.io.IOException;
022import java.io.InputStreamReader;
023
024import 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 * @see DaytimeUDPClient
038 ***/
039
040public final class DaytimeTCPClient extends SocketClient
041{
042    /*** The default daytime port.  It is set to 13 according to RFC 867. ***/
043    public static final int DEFAULT_PORT = 13;
044
045    // Received dates will likely be less than 64 characters.
046    // This is a temporary buffer used while receiving data.
047    private final char[] __buffer = new char[64];
048
049    /***
050     * The default DaytimeTCPClient constructor.  It merely sets the default
051     * port to <code> DEFAULT_PORT </code>.
052     ***/
053    public DaytimeTCPClient ()
054    {
055        setDefaultPort(DEFAULT_PORT);
056    }
057
058    /***
059     * Retrieves the time string from the server and returns it.  The
060     * server will have closed the connection at this point, so you should
061     * call
062     * {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
063     * after calling this method.  To retrieve another time, you must
064     * initiate another connection with
065     * {@link org.apache.commons.net.SocketClient#connect  connect }
066     * before calling <code> getTime() </code> again.
067     * <p>
068     * @return The time string retrieved from the server.
069     * @exception IOException  If an error occurs while fetching the time string.
070     ***/
071    public String getTime() throws IOException
072    {
073        int read;
074        StringBuilder result = new StringBuilder(__buffer.length);
075        BufferedReader reader;
076
077        reader = new BufferedReader(new InputStreamReader(_input_));
078
079        while (true)
080        {
081            read = reader.read(__buffer, 0, __buffer.length);
082            if (read <= 0) {
083                break;
084            }
085            result.append(__buffer, 0, read);
086        }
087
088        return result.toString();
089    }
090
091}
092