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