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 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 StringBuffer result = new StringBuffer(__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