1 /* LineInputStream.java --
2 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
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)
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.
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., 59 Temple Place, Suite 330, Boston, MA
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
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. */
41 import java.io.ByteArrayOutputStream;
42 import java.io.FilterInputStream;
43 import java.io.InputStream;
44 import java.io.IOException;
47 * An input stream that can read lines of input.
49 * @author Chris Burdess (dog@gnu.org)
51 public class LineInputStream
52 extends FilterInputStream
57 private ByteArrayOutputStream buf;
60 * Encoding to use when translating bytes to characters.
62 private String encoding;
70 * Whether we can use block reads.
72 private final boolean blockReads;
75 * Constructor using the US-ASCII character encoding.
76 * @param in the underlying input stream
78 public LineInputStream(InputStream in)
85 * @param in the underlying input stream
86 * @param encoding the character encoding to use
88 public LineInputStream(InputStream in, String encoding)
91 buf = new ByteArrayOutputStream();
92 this.encoding = encoding;
94 blockReads = in.markSupported();
98 * Read a line of input.
100 public String readLine()
111 // Use mark and reset to read chunks of bytes
112 final int MIN_LENGTH = 1024;
115 len = in.available();
116 len = (len < MIN_LENGTH) ? MIN_LENGTH : len;
117 byte[] b = new byte[len];
119 // Read into buffer b
120 len = in.read(b, 0, len);
131 // We don't care about resetting buf
132 return buf.toString(encoding);
135 // Get index of LF in b
136 pos = indexOf(b, len, (byte) 0x0a);
139 // Write pos bytes to buf
140 buf.write(b, 0, pos);
141 // Reset stream, and read pos + 1 bytes
146 len = in.read(b, 0, pos);
147 pos = (len == -1) ? -1 : pos - len;
150 String ret = buf.toString(encoding);
156 // Append everything to buf and fall through to re-read.
157 buf.write(b, 0, len);
162 // We must use character reads in order not to read too much
163 // from the underlying stream.
173 // Fall through and return contents of buffer.
175 String ret = buf.toString(encoding);
186 private int indexOf(byte[] b, int len, byte c)
188 for (int pos = 0; pos < len; pos++)