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 * @see DaytimeUDPClient 038 ***/ 039 040 public final class DaytimeTCPClient extends SocketClient 041 { 042 /*** The default daytime port. It is set to 13 according to RFC 867. ***/ 043 public static final int DEFAULT_PORT = 13; 044 045 // Received dates will likely be less than 64 characters. 046 // This is a temporary buffer used while receiving data. 047 private final char[] __buffer = new char[64]; 048 049 /*** 050 * The default DaytimeTCPClient constructor. It merely sets the default 051 * port to <code> DEFAULT_PORT </code>. 052 ***/ 053 public DaytimeTCPClient () 054 { 055 setDefaultPort(DEFAULT_PORT); 056 } 057 058 /*** 059 * Retrieves the time string from the server and returns it. The 060 * server will have closed the connection at this point, so you should 061 * call 062 * {@link org.apache.commons.net.SocketClient#disconnect disconnect } 063 * after calling this method. To retrieve another time, you must 064 * initiate another connection with 065 * {@link org.apache.commons.net.SocketClient#connect connect } 066 * before calling <code> getTime() </code> again. 067 * <p> 068 * @return The time string retrieved from the server. 069 * @exception IOException If an error occurs while fetching the time string. 070 ***/ 071 public String getTime() throws IOException 072 { 073 int read; 074 StringBuilder result = new StringBuilder(__buffer.length); 075 BufferedReader reader; 076 077 reader = new BufferedReader(new InputStreamReader(_input_)); 078 079 while (true) 080 { 081 read = reader.read(__buffer, 0, __buffer.length); 082 if (read <= 0) { 083 break; 084 } 085 result.append(__buffer, 0, read); 086 } 087 088 return result.toString(); 089 } 090 091 } 092