/*
* Copyright 2001-2005 The Apache Software Foundation
*
* Licensed 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.
*/
package org.apache.commons.net.io;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/***
* This class wraps an output stream, replacing all singly occurring
* <LF> (linefeed) characters with <CR><LF> (carriage return
* followed by linefeed), which is the NETASCII standard for representing
* a newline.
* You would use this class to implement ASCII file transfers requiring
* conversion to NETASCII.
* <p>
* <p>
* @author Daniel F. Savarese
***/
public final class ToNetASCIIOutputStream extends FilterOutputStream
{
private boolean __lastWasCR;
/***
* Creates a ToNetASCIIOutputStream instance that wraps an existing
* OutputStream.
* <p>
* @param output The OutputStream to wrap.
***/
public ToNetASCIIOutputStream(OutputStream output)
{
super(output);
__lastWasCR = false;
}
/***
* Writes a byte to the stream. Note that a call to this method
* may result in multiple writes to the underlying input stream in order
* to convert naked newlines to NETASCII line separators.
* This is transparent to the programmer and is only mentioned for
* completeness.
* <p>
* @param ch The byte to write.
* @exception IOException If an error occurs while writing to the underlying
* stream.
***/
public synchronized void write(int ch)
throws IOException
{
switch (ch)
{
case '\r':
__lastWasCR = true;
out.write('\r');
return ;
case '\n':
if (!__lastWasCR)
out.write('\r');
// Fall through
default:
__lastWasCR = false;
out.write(ch);
return ;
}
}
/***
* Writes a byte array to the stream.
* <p>
* @param buffer The byte array to write.
* @exception IOException If an error occurs while writing to the underlying
* stream.
***/
public synchronized void write(byte buffer[])
throws IOException
{
write(buffer, 0, buffer.length);
}
/***
* Writes a number of bytes from a byte array to the stream starting from
* a given offset.
* <p>
* @param buffer The byte array to write.
* @param offset The offset into the array at which to start copying data.
* @param length The number of bytes to write.
* @exception IOException If an error occurs while writing to the underlying
* stream.
***/
public synchronized void write(byte buffer[], int offset, int length)
throws IOException
{
while (length-- > 0)
write(buffer[offset++]);
}
}
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