1 /* CRLFInputStream.java -- 2 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.java.net; 40 41 import java.io.BufferedInputStream; 42 import java.io.FilterInputStream; 43 import java.io.IOException; 44 import java.io.InputStream; 45 46 /** 47 * An input stream that filters out CR/LF pairs into LFs. 48 * 49 * @author Chris Burdess (dog@gnu.org) 50 */ 51 public class CRLFInputStream 52 extends FilterInputStream 53 { 54 /** 55 * The CR octet. 56 */ 57 public static final int CR = 13; 58 59 /** 60 * The LF octet. 61 */ 62 public static final int LF = 10; 63 64 private boolean doReset; 65 66 /** 67 * Constructs a CR/LF input stream connected to the specified input 68 * stream. 69 */ CRLFInputStream(InputStream in)70 public CRLFInputStream(InputStream in) 71 { 72 super(in.markSupported() ? in : new BufferedInputStream(in)); 73 } 74 75 /** 76 * Reads the next byte of data from this input stream. 77 * Returns -1 if the end of the stream has been reached. 78 * @exception IOException if an I/O error occurs 79 */ read()80 public int read() 81 throws IOException 82 { 83 int c = in.read(); 84 if (c == CR) 85 { 86 in.mark(1); 87 int d = in.read(); 88 if (d == LF) 89 { 90 c = d; 91 } 92 else 93 { 94 in.reset(); 95 } 96 } 97 return c; 98 } 99 100 /** 101 * Reads up to b.length bytes of data from this input stream into 102 * an array of bytes. 103 * Returns -1 if the end of the stream has been reached. 104 * @exception IOException if an I/O error occurs 105 */ read(byte[] b)106 public int read(byte[] b) 107 throws IOException 108 { 109 return read(b, 0, b.length); 110 } 111 112 /** 113 * Reads up to len bytes of data from this input stream into an 114 * array of bytes, starting at the specified offset. 115 * Returns -1 if the end of the stream has been reached. 116 * @exception IOException if an I/O error occurs 117 */ read(byte[] b, int off, int len)118 public int read(byte[] b, int off, int len) 119 throws IOException 120 { 121 in.mark(len + 1); 122 int l = in.read(b, off, len); 123 if (l > 0) 124 { 125 int i = indexOfCRLF(b, off, l); 126 if (doReset) 127 { 128 in.reset(); 129 if (i != -1) 130 { 131 l = in.read(b, off, i + 1); // read to CR 132 in.read(); // skip LF 133 b[i] = LF; // fix CR as LF 134 } 135 else 136 { 137 l = in.read(b, off, len); // CR(s) but no LF 138 } 139 } 140 } 141 return l; 142 } 143 indexOfCRLF(byte[] b, int off, int len)144 private int indexOfCRLF(byte[] b, int off, int len) 145 throws IOException 146 { 147 doReset = false; 148 int lm1 = len - 1; 149 for (int i = off; i < len; i++) 150 { 151 if (b[i] == CR) 152 { 153 int d; 154 if (i == lm1) 155 { 156 d = in.read(); 157 doReset = true; 158 } 159 else 160 { 161 d = b[i + 1]; 162 } 163 if (d == LF) 164 { 165 doReset = true; 166 return i; 167 } 168 } 169 } 170 return -1; 171 } 172 173 } 174 175