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    1   /*
    2    * Copyright 2001-2005 The Apache Software Foundation
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *     http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.net;
    17
    18  import java.io.BufferedReader;
    19  import java.io.IOException;
    20  import java.io.InputStreamReader;
    21
    22  /****
    23   * The DaytimeTCPClient class is a TCP implementation of a client for the
    24   * Daytime protocol described in RFC 867.  To use the class, merely
    25   * establish a connection with
    26   * {@link org.apache.commons.net.SocketClient#connect  connect }
    27   * and call {@link #getTime  getTime() } to retrieve the daytime
    28   * string, then
    29   * call {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
    30   * to close the connection properly.
    31   * <p>
    32   * <p>
    33   * @author Daniel F. Savarese
    34   * @see DaytimeUDPClient
    35   ***/
    36
    37  public final class DaytimeTCPClient extends SocketClient
    38  {
    39      /**** The default daytime port.  It is set to 13 according to RFC 867. ***/
    40      public static final int DEFAULT_PORT = 13;
    41
    42      // Received dates will likely be less than 64 characters.
    43      // This is a temporary buffer used while receiving data.
    44      private char[] __buffer = new char[64];
    45
    46      /****
    47       * The default DaytimeTCPClient constructor.  It merely sets the default
    48       * port to <code> DEFAULT_PORT </code>.
    49       ***/
    50      public DaytimeTCPClient ()
    51      {
    52          setDefaultPort(DEFAULT_PORT);
    53      }
    54
    55      /****
    56       * Retrieves the time string from the server and returns it.  The
    57       * server will have closed the connection at this point, so you should
    58       * call
    59       * {@link org.apache.commons.net.SocketClient#disconnect  disconnect }
    60       * after calling this method.  To retrieve another time, you must
    61       * initiate another connection with
    62       * {@link org.apache.commons.net.SocketClient#connect  connect }
    63       * before calling <code> getTime() </code> again.
    64       * <p>
    65       * @return The time string retrieved from the server.
    66       * @exception IOException  If an error occurs while fetching the time string.
    67       ***/
    68      public String getTime() throws IOException
    69      {
    70          int read;
    71          StringBuffer result = new StringBuffer(__buffer.length);
    72          BufferedReader reader;
    73
    74          reader = new BufferedReader(new InputStreamReader(_input_));
    75
    76          while (true)
    77          {
    78              read = reader.read(__buffer, 0, __buffer.length);
    79              if (read <= 0)
    80                  break;
    81              result.append(__buffer, 0, read);
    82          }
    83
    84          return result.toString();
    85      }
    86
    87  }
    88