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 package org.apache.commons.net;
18
19 import java.io.BufferedReader;
20 import java.io.IOException;
21 import java.io.InputStreamReader;
22
23 /***
24 * The DaytimeTCPClient class is a TCP implementation of a client for the
25 * Daytime protocol described in RFC 867. To use the class, merely
26 * establish a connection with
27 * {@link org.apache.commons.net.SocketClient#connect connect }
28 * and call {@link #getTime getTime() } to retrieve the daytime
29 * string, then
30 * call {@link org.apache.commons.net.SocketClient#disconnect disconnect }
31 * to close the connection properly.
32 * <p>
33 * <p>
34 * @author Daniel F. Savarese
35 * @see DaytimeUDPClient
36 ***/
37
38 public final class DaytimeTCPClient extends SocketClient
39 {
40 /*** The default daytime port. It is set to 13 according to RFC 867. ***/
41 public static final int DEFAULT_PORT = 13;
42
43 // Received dates will likely be less than 64 characters.
44 // This is a temporary buffer used while receiving data.
45 private char[] __buffer = new char[64];
46
47 /***
48 * The default DaytimeTCPClient constructor. It merely sets the default
49 * port to <code> DEFAULT_PORT </code>.
50 ***/
51 public DaytimeTCPClient ()
52 {
53 setDefaultPort(DEFAULT_PORT);
54 }
55
56 /***
57 * Retrieves the time string from the server and returns it. The
58 * server will have closed the connection at this point, so you should
59 * call
60 * {@link org.apache.commons.net.SocketClient#disconnect disconnect }
61 * after calling this method. To retrieve another time, you must
62 * initiate another connection with
63 * {@link org.apache.commons.net.SocketClient#connect connect }
64 * before calling <code> getTime() </code> again.
65 * <p>
66 * @return The time string retrieved from the server.
67 * @exception IOException If an error occurs while fetching the time string.
68 ***/
69 public String getTime() throws IOException
70 {
71 int read;
72 StringBuffer result = new StringBuffer(__buffer.length);
73 BufferedReader reader;
74
75 reader = new BufferedReader(new InputStreamReader(_input_));
76
77 while (true)
78 {
79 read = reader.read(__buffer, 0, __buffer.length);
80 if (read <= 0)
81 break;
82 result.append(__buffer, 0, read);
83 }
84
85 return result.toString();
86 }
87
88 }
89