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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.net.daytime;
19  
20  import java.io.BufferedReader;
21  import java.io.IOException;
22  import java.io.InputStreamReader;
23  
24  import org.apache.commons.net.SocketClient;
25  
26  /***
27   * The DaytimeTCPClient class is a TCP implementation of a client for the
28   * Daytime protocol described in RFC 867.  To use the class, merely
29   * establish a connection with
30   * {@link org.apache.commons.net.SocketClient#connect  connect }
31   * and call {@link #getTime  getTime() } to retrieve the daytime
32   * string, then
33   * call {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
34   * to close the connection properly.
35   * <p>
36   * <p>
37   * @author Daniel F. Savarese
38   * @see DaytimeUDPClient
39   ***/
40  
41  public final class DaytimeTCPClient extends SocketClient
42  {
43      /*** The default daytime port.  It is set to 13 according to RFC 867. ***/
44      public static final int DEFAULT_PORT = 13;
45  
46      // Received dates will likely be less than 64 characters.
47      // This is a temporary buffer used while receiving data.
48      private char[] __buffer = new char[64];
49  
50      /***
51       * The default DaytimeTCPClient constructor.  It merely sets the default
52       * port to <code> DEFAULT_PORT </code>.
53       ***/
54      public DaytimeTCPClient ()
55      {
56          setDefaultPort(DEFAULT_PORT);
57      }
58  
59      /***
60       * Retrieves the time string from the server and returns it.  The
61       * server will have closed the connection at this point, so you should
62       * call
63       * {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
64       * after calling this method.  To retrieve another time, you must
65       * initiate another connection with
66       * {@link org.apache.commons.net.SocketClient#connect  connect }
67       * before calling <code> getTime() </code> again.
68       * <p>
69       * @return The time string retrieved from the server.
70       * @exception IOException  If an error occurs while fetching the time string.
71       ***/
72      public String getTime() throws IOException
73      {
74          int read;
75          StringBuffer result = new StringBuffer(__buffer.length);
76          BufferedReader reader;
77  
78          reader = new BufferedReader(new InputStreamReader(_input_));
79  
80          while (true)
81          {
82              read = reader.read(__buffer, 0, __buffer.length);
83              if (read <= 0)
84                  break;
85              result.append(__buffer, 0, read);
86          }
87  
88          return result.toString();
89      }
90  
91  }
92