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/****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one *
* or more contributor license agreements. See the NOTICE file *
* distributed with this work for additional information *
* regarding copyright ownership. The ASF licenses this file *
* to you under the Apache License, Version 2.0 (the *
* "License"); you may not use this file except in compliance *
* with the License. You may obtain a copy of the License at *
* *
* http://www.apache.org/licenses/LICENSE-2.0 *
* *
* Unless required by applicable law or agreed to in writing, *
* software distributed under the License is distributed on an *
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
* KIND, either express or implied. See the License for the *
* specific language governing permissions and limitations *
* under the License. *
****************************************************************/
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
/**
* InputStream which converts <code>\r</code>
* bytes not followed by <code>\n</code> and <code>\n</code> not
* preceded by <code>\r</code> to <code>\r\n</code>.
*/
public class EOLConvertingInputStream extends InputStream {
/** Converts single '\r' to '\r\n' */
public static final int CONVERT_CR = 1;
/** Converts single '\n' to '\r\n' */
public static final int CONVERT_LF = 2;
/** Converts single '\r' and '\n' to '\r\n' */
public static final int CONVERT_BOTH = 3;
private PushbackInputStream in = null;
private int previous = 0;
private int flags = CONVERT_BOTH;
/**
* Creates a new <code>EOLConvertingInputStream</code>
* instance converting bytes in the given <code>InputStream</code>.
* The flag <code>CONVERT_BOTH</code> is the default.
*
* @param in the <code>InputStream</code> to read from.
*/
public EOLConvertingInputStream(InputStream in) {
this(in, CONVERT_BOTH);
}
/**
* Creates a new <code>EOLConvertingInputStream</code>
* instance converting bytes in the given <code>InputStream</code>.
*
* @param in the <code>InputStream</code> to read from.
* @param flags one of <code>CONVERT_CR</code>, <code>CONVERT_LF</code> or
* <code>CONVERT_BOTH</code>.
*/
public EOLConvertingInputStream(InputStream in, int flags) {
super();
this.in = new PushbackInputStream(in, 2);
this.flags = flags;
}
/**
* Closes the underlying stream.
*
* @throws IOException on I/O errors.
*/
@Override
public void close() throws IOException {
in.close();
}
/**
* @see java.io.InputStream#read()
*/
@Override
public int read() throws IOException {
int b = in.read();
if (b == -1) {
return -1;
}
if ((flags & CONVERT_CR) != 0 && b == '\r') {
int c = in.read();
if (c != -1) {
in.unread(c);
}
if (c != '\n') {
in.unread('\n');
}
} else if ((flags & CONVERT_LF) != 0 && b == '\n' && previous != '\r') {
b = '\r';
in.unread('\n');
}
previous = b;
return b;
}
}
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