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1 package org.apache.commons.net.io; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache Commons" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import java.io.FilterInputStream; 58 import java.io.IOException; 59 import java.io.InputStream; 60 61 /**** 62 * This class wraps an input stream, replacing all singly occurring 63 * <LF> (linefeed) characters with <CR><LF> (carriage return 64 * followed by linefeed), which is the NETASCII standard for representing 65 * a newline. 66 * You would use this class to implement ASCII file transfers requiring 67 * conversion to NETASCII. 68 * <p> 69 * <p> 70 * @author Daniel F. Savarese 71 ***/ 72 73 public final class ToNetASCIIInputStream extends FilterInputStream 74 { 75 private static final int __NOTHING_SPECIAL = 0; 76 private static final int __LAST_WAS_CR = 1; 77 private static final int __LAST_WAS_NL = 2; 78 private int __status; 79 80 /**** 81 * Creates a ToNetASCIIInputStream instance that wraps an existing 82 * InputStream. 83 * <p> 84 * @param input The InputStream to . 85 ***/ 86 public ToNetASCIIInputStream(InputStream input) 87 { 88 super(input); 89 __status = __NOTHING_SPECIAL; 90 } 91 92 93 /**** 94 * Reads and returns the next byte in the stream. If the end of the 95 * message has been reached, returns -1. 96 * <p> 97 * @return The next character in the stream. Returns -1 if the end of the 98 * stream has been reached. 99 * @exception IOException If an error occurs while reading the underlying 100 * stream. 101 ***/ 102 public int read() throws IOException 103 { 104 int ch; 105 106 if (__status == __LAST_WAS_NL) 107 { 108 __status = __NOTHING_SPECIAL; 109 return '\n'; 110 } 111 112 ch = in.read(); 113 114 switch (ch) 115 { 116 case '\r': 117 __status = __LAST_WAS_CR; 118 return '\r'; 119 case '\n': 120 if (__status != __LAST_WAS_CR) 121 { 122 __status = __LAST_WAS_NL; 123 return '\r'; 124 } 125 // else fall through 126 default: 127 __status = __NOTHING_SPECIAL; 128 return ch; 129 } 130 // statement not reached 131 //return ch; 132 } 133 134 135 /**** 136 * Reads the next number of bytes from the stream into an array and 137 * returns the number of bytes read. Returns -1 if the end of the 138 * stream has been reached. 139 * <p> 140 * @param buffer The byte array in which to store the data. 141 * @return The number of bytes read. Returns -1 if the 142 * end of the message has been reached. 143 * @exception IOException If an error occurs in reading the underlying 144 * stream. 145 ***/ 146 public int read(byte buffer[]) throws IOException 147 { 148 return read(buffer, 0, buffer.length); 149 } 150 151 152 /**** 153 * Reads the next number of bytes from the stream into an array and returns 154 * the number of bytes read. Returns -1 if the end of the 155 * message has been reached. The characters are stored in the array 156 * starting from the given offset and up to the length specified. 157 * <p> 158 * @param buffer The byte array in which to store the data. 159 * @param offset The offset into the array at which to start storing data. 160 * @param length The number of bytes to read. 161 * @return The number of bytes read. Returns -1 if the 162 * end of the stream has been reached. 163 * @exception IOException If an error occurs while reading the underlying 164 * stream. 165 ***/ 166 public int read(byte buffer[], int offset, int length) throws IOException 167 { 168 int ch, off; 169 170 if (length < 1) 171 return 0; 172 173 ch = available(); 174 175 if (length > ch) 176 length = ch; 177 178 // If nothing is available, block to read only one character 179 if (length < 1) 180 length = 1; 181 182 if ((ch = read()) == -1) 183 return -1; 184 185 off = offset; 186 187 do 188 { 189 buffer[offset++] = (byte)ch; 190 } 191 while (--length > 0 && (ch = read()) != -1); 192 193 return (offset - off); 194 } 195 196 /**** Returns false. Mark is not supported. ***/ 197 public boolean markSupported() 198 { 199 return false; 200 } 201 202 public int available() throws IOException 203 { 204 int result; 205 206 result = in.available(); 207 208 if (__status == __LAST_WAS_NL) 209 return (result + 1); 210 211 return result; 212 } 213 }

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