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 * @see DaytimeUDPClient 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 final 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 StringBuilder result = new StringBuilder(__buffer.length); 72 BufferedReader reader; 73 74 reader = new BufferedReader(new InputStreamReader(_input_, getCharsetName())); // Java 1.6 can use getCharset() 75 76 while (true) 77 { 78 read = reader.read(__buffer, 0, __buffer.length); 79 if (read <= 0) { 80 break; 81 } 82 result.append(__buffer, 0, read); 83 } 84 85 return result.toString(); 86 } 87 88 } 89