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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: */ 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: */ 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: */ 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: */ 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: 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: }