/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @(#)LineInputStream.java 1.7 03/01/07
*/
package com.sun.xml.internal.messaging.saaj.packaging.mime.util;
import java.io.*;
/**
* This class is to support reading CRLF terminated lines that
* contain only US-ASCII characters from an input stream. Provides
* functionality that is similar to the deprecated
* <code>DataInputStream.readLine()</code>. Expected use is to read
* lines as String objects from a RFC822 stream.
*
* It is implemented as a FilterInputStream, so one can just wrap
* this class around any input stream and read bytes from this filter.
*
* @author John Mani
*/
public final class LineInputStream extends FilterInputStream {
private char[] lineBuffer = null; // reusable byte buffer
public LineInputStream(InputStream in) {
super(in);
}
/**
* Read a line containing only ASCII characters from the input
* stream. A line is terminated by a CR or NL or CR-NL sequence.
* A common error is a CR-CR-NL sequence, which will also terminate
* a line.
* The line terminator is not returned as part of the returned
* String. Returns null if no data is available. <p>
*
* This class is similar to the deprecated
* <code>DataInputStream.readLine()</code>
*/
public String readLine() throws IOException {
InputStream in = this.in;
char[] buf = lineBuffer;
if (buf == null)
buf = lineBuffer = new char[128];
int c1;
int room = buf.length;
int offset = 0;
while ((c1 = in.read()) != -1) {
if (c1 == '\n') // Got NL, outa here.
break;
else if (c1 == '\r') {
// Got CR, is the next char NL ?
int c2 = in.read();
if (c2 == '\r') // discard extraneous CR
c2 = in.read();
if (c2 != '\n') {
// If not NL, push it back
if (!(in instanceof PushbackInputStream))
in = this.in = new PushbackInputStream(in);
((PushbackInputStream)in).unread(c2);
}
break; // outa here.
}
// Not CR, NL or CR-NL ...
// .. Insert the byte into our byte buffer
if (--room < 0) { // No room, need to grow.
buf = new char[offset + 128];
room = buf.length - offset - 1;
System.arraycopy(lineBuffer, 0, buf, 0, offset);
lineBuffer = buf;
}
buf[offset++] = (char)c1;
}
if ((c1 == -1) && (offset == 0))
return null;
return String.copyValueOf(buf, 0, offset);
}
}