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1: /* 2: * MessageInputStream.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.FilterInputStream; 42: import java.io.InputStream; 43: import java.io.IOException; 44: 45: /** 46: * A utility class for feeding message contents to messages. 47: * This stream returns -1 from <code>read</code> when the stream termination 48: * sequence LF,END,LF is read from the underlying stream. 49: * 50: * @author <a href="mailto:dog@gnu.org">Chris Burdess</a> 51: */ 52: public class MessageInputStream 53: extends FilterInputStream 54: { 55: 56: /** 57: * The stream termination octet ('.'). 58: */ 59: public static final int END = 46; 60: 61: /** 62: * The line termination octet ('\n'). 63: */ 64: public static final int LF = 10; 65: 66: protected boolean eof; 67: 68: protected int buf1 = -1; 69: protected int buf2 = -1; 70: 71: protected int markBuf1; 72: protected int markBuf2; 73: 74: /** 75: * Constructs a message input stream connected to the specified input stream. 76: */ 77: public MessageInputStream(InputStream in) 78: { 79: super(in); 80: eof = false; 81: } 82: 83: /** 84: * Reads the next byte of data from this message input stream. 85: * Returns -1 if the end of the message stream has been reached. 86: * @exception IOException if an I/O error occurs 87: */ 88: public int read() 89: throws IOException 90: { 91: if (eof) 92: { 93: return -1; 94: } 95: int c; 96: if (buf1 != -1) 97: { 98: c = buf1; 99: buf1 = buf2; 100: buf2 = -1; 101: } 102: else 103: { 104: c = super.read(); 105: } 106: if (c == LF) 107: { 108: if (buf1 == -1) 109: { 110: buf1 = super.read(); 111: if (buf1 == END) 112: { 113: buf2 = super.read(); 114: if (buf2 == LF) 115: { 116: eof = true; 117: // Allow the final LF to be read 118: } 119: } 120: } 121: else if (buf1 == END) 122: { 123: if (buf2 == -1) 124: { 125: buf2 = super.read(); 126: if (buf2 == LF) 127: { 128: eof = true; 129: } 130: } 131: else if (buf2 == LF) 132: { 133: eof = true; 134: } 135: } 136: } 137: return c; 138: } 139: 140: /** 141: * Reads up to b.length bytes of data from this input stream into 142: * an array of bytes. 143: * Returns -1 if the end of the stream has been reached. 144: * @exception IOException if an I/O error occurs 145: */ 146: public int read(byte[] b) 147: throws IOException 148: { 149: return read(b, 0, b.length); 150: } 151: 152: /** 153: * Reads up to len bytes of data from this input stream into an 154: * array of bytes, starting at the specified offset. 155: * Returns -1 if the end of the stream has been reached. 156: * @exception IOException if an I/O error occurs 157: */ 158: public int read(byte[] b, int off, int len) 159: throws IOException 160: { 161: if (eof) 162: { 163: return -1; 164: } 165: int c, end = off + len; 166: for (int i = off; i < end; i++) 167: { 168: c = read(); 169: if (c == -1) 170: { 171: len = i - off; 172: break; 173: } 174: else 175: { 176: b[i] = (byte) c; 177: } 178: } 179: return len; 180: } 181: 182: public boolean markSupported() 183: { 184: return in.markSupported(); 185: } 186: 187: public void mark(int readlimit) 188: { 189: in.mark(readlimit); 190: markBuf1 = buf1; 191: markBuf2 = buf2; 192: } 193: 194: public void reset() 195: throws IOException 196: { 197: in.reset(); 198: buf1 = markBuf1; 199: buf2 = markBuf2; 200: } 201: 202: }