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1: /* 2: * CRLFInputStream.java 3: * Copyright (C) 2002 The Free Software Foundation 4: * 5: * This file is part of GNU inetlib, a library. 6: * 7: * GNU inetlib is free software; you can redistribute it and/or modify 8: * it under the terms of the GNU General Public License as published by 9: * the Free Software Foundation; either version 2 of the License, or 10: * (at your option) any later version. 11: * 12: * GNU inetlib is distributed in the hope that it will be useful, 13: * but WITHOUT ANY WARRANTY; without even the implied warranty of 14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15: * GNU General Public License for more details. 16: * 17: * You should have received a copy of the GNU General Public License 18: * along with this library; if not, write to the Free Software 19: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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: * obliged to do so. If you do not wish to do so, delete this 36: * exception statement from your version. 37: */ 38: 39: package gnu.inet.util; 40: 41: import java.io.BufferedInputStream; 42: import java.io.FilterInputStream; 43: import java.io.InputStream; 44: import java.io.IOException; 45: 46: /** 47: * An input stream that filters out CR/LF pairs into LFs. 48: * 49: * @author <a href="mailto:dog@gnu.org">Chris Burdess</a> 50: */ 51: public class CRLFInputStream 52: extends FilterInputStream 53: { 54: 55: /** 56: * The CR octet. 57: */ 58: public static final int CR = 13; 59: 60: /** 61: * The LF octet. 62: */ 63: public static final int LF = 10; 64: 65: private boolean doReset; 66: 67: /** 68: * Constructs a CR/LF input stream connected to the specified input 69: * stream. 70: */ 71: public CRLFInputStream(InputStream in) 72: { 73: super(in.markSupported() ? in : new BufferedInputStream(in)); 74: } 75: 76: /** 77: * Reads the next byte of data from this input stream. 78: * Returns -1 if the end of the stream has been reached. 79: * @exception IOException if an I/O error occurs 80: */ 81: public int read() 82: throws IOException 83: { 84: int c = in.read(); 85: if (c == CR) 86: { 87: in.mark(1); 88: int d = in.read(); 89: if (d == LF) 90: { 91: c = d; 92: } 93: else 94: { 95: in.reset(); 96: } 97: } 98: return c; 99: } 100: 101: /** 102: * Reads up to b.length bytes of data from this input stream into 103: * an array of bytes. 104: * Returns -1 if the end of the stream has been reached. 105: * @exception IOException if an I/O error occurs 106: */ 107: public int read(byte[] b) 108: throws IOException 109: { 110: return read(b, 0, b.length); 111: } 112: 113: /** 114: * Reads up to len bytes of data from this input stream into an 115: * array of bytes, starting at the specified offset. 116: * Returns -1 if the end of the stream has been reached. 117: * @exception IOException if an I/O error occurs 118: */ 119: public int read(byte[] b, int off, int len) 120: throws IOException 121: { 122: in.mark(len + 1); 123: int l = in.read(b, off, len); 124: if (l > 0) 125: { 126: int i = indexOfCRLF(b, off, l); 127: if (doReset) 128: { 129: in.reset(); 130: if (i != -1) 131: { 132: l = in.read(b, off, i + 1); // read to CR 133: in.read(); // skip LF 134: b[i] = LF; // fix CR as LF 135: } 136: else 137: { 138: l = in.read(b, off, len); // CR(s) but no LF 139: } 140: } 141: } 142: return l; 143: } 144: 145: private int indexOfCRLF(byte[] b, int off, int len) 146: throws IOException 147: { 148: doReset = false; 149: int lm1 = len - 1; 150: for (int i = off; i < len; i++) 151: { 152: if (b[i] == CR) 153: { 154: int d; 155: if (i == lm1) 156: { 157: d = in.read(); 158: doReset = true; 159: } 160: else 161: { 162: d = b[i + 1]; 163: } 164: if (d == LF) 165: { 166: doReset = true; 167: return i; 168: } 169: } 170: } 171: return -1; 172: } 173: 174: }