What this is
This file is included in the DevDaily.com
"Java Source Code
Warehouse" project. The intent of this project is to help you "Learn
Java by Example" TM.
Other links
The source code
/*
* Copyright 2001-2004 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.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
/***
* The Util class cannot be instantiated and stores short static convenience
* methods that are often quite useful.
*
*
* @see CopyStreamException
* @see CopyStreamListener
* @see CopyStreamAdapter
* @author Daniel F. Savarese
***/
public final class Util
{
/***
* The default buffer size used by copyStream
* and copyReader . It's value is 1024.
***/
public static final int DEFAULT_COPY_BUFFER_SIZE = 1024;
// Cannot be instantiated
private Util()
{ }
/***
* Copies the contents of an InputStream to an OutputStream using a
* copy buffer of a given size and notifies the provided
* CopyStreamListener of the progress of the copy operation by calling
* its bytesTransferred(long, int) method after each write to the
* destination. If you wish to notify more than one listener you should
* use a CopyStreamAdapter as the listener and register the additional
* listeners with the CopyStreamAdapter.
*
* The contents of the InputStream are
* read until the end of the stream is reached, but neither the
* source nor the destination are closed. You must do this yourself
* outside of the method call. The number of bytes read/written is
* returned.
*
* @param source The source InputStream.
* @param dest The destination OutputStream.
* @param bufferSize The number of bytes to buffer during the copy.
* @param streamSize The number of bytes in the stream being copied.
* Should be set to CopyStreamEvent.UNKNOWN_STREAM_SIZE if unknown.
* @param listener The CopyStreamListener to notify of progress. If
* this parameter is null, notification is not attempted.
* @exception CopyStreamException If an error occurs while reading from the
* source or writing to the destination. The CopyStreamException
* will contain the number of bytes confirmed to have been
* transferred before an
* IOException occurred, and it will also contain the IOException
* that caused the error. These values can be retrieved with
* the CopyStreamException getTotalBytesTransferred() and
* getIOException() methods.
***/
public static final long copyStream(InputStream source, OutputStream dest,
int bufferSize, long streamSize,
CopyStreamListener listener)
throws CopyStreamException
{
int bytes;
long total;
byte[] buffer;
buffer = new byte[bufferSize];
total = 0;
try
{
while ((bytes = source.read(buffer)) != -1)
{
// Technically, some read(byte[]) methods may return 0 and we cannot
// accept that as an indication of EOF.
if (bytes == 0)
{
bytes = source.read();
if (bytes < 0)
break;
dest.write(bytes);
dest.flush();
++total;
if (listener != null)
listener.bytesTransferred(total, 1, streamSize);
continue;
}
dest.write(buffer, 0, bytes);
dest.flush();
total += bytes;
if (listener != null)
listener.bytesTransferred(total, bytes, streamSize);
}
}
catch (IOException e)
{
throw new CopyStreamException("IOException caught while copying.",
total, e);
}
return total;
}
/***
* Copies the contents of an InputStream to an OutputStream using a
* copy buffer of a given size. The contents of the InputStream are
* read until the end of the stream is reached, but neither the
* source nor the destination are closed. You must do this yourself
* outside of the method call. The number of bytes read/written is
* returned.
*
* @param source The source InputStream.
* @param dest The destination OutputStream.
* @return The number of bytes read/written in the copy operation.
* @exception CopyStreamException If an error occurs while reading from the
* source or writing to the destination. The CopyStreamException
* will contain the number of bytes confirmed to have been
* transferred before an
* IOException occurred, and it will also contain the IOException
* that caused the error. These values can be retrieved with
* the CopyStreamException getTotalBytesTransferred() and
* getIOException() methods.
***/
public static final long copyStream(InputStream source, OutputStream dest,
int bufferSize)
throws CopyStreamException
{
return copyStream(source, dest, bufferSize,
CopyStreamEvent.UNKNOWN_STREAM_SIZE, null);
}
/***
* Same as copyStream(source, dest, DEFAULT_COPY_BUFFER_SIZE);
***/
public static final long copyStream(InputStream source, OutputStream dest)
throws CopyStreamException
{
return copyStream(source, dest, DEFAULT_COPY_BUFFER_SIZE);
}
/***
* Copies the contents of a Reader to a Writer using a
* copy buffer of a given size and notifies the provided
* CopyStreamListener of the progress of the copy operation by calling
* its bytesTransferred(long, int) method after each write to the
* destination. If you wish to notify more than one listener you should
* use a CopyStreamAdapter as the listener and register the additional
* listeners with the CopyStreamAdapter.
*
* The contents of the Reader are
* read until its end is reached, but neither the source nor the
* destination are closed. You must do this yourself outside of the
* method call. The number of characters read/written is returned.
*
* @param source The source Reader.
* @param dest The destination writer.
* @param bufferSize The number of characters to buffer during the copy.
* @param streamSize The number of characters in the stream being copied.
* Should be set to CopyStreamEvent.UNKNOWN_STREAM_SIZE if unknown.
* @param listener The CopyStreamListener to notify of progress. If
* this parameter is null, notification is not attempted.
* @return The number of characters read/written in the copy operation.
* @exception CopyStreamException If an error occurs while reading from the
* source or writing to the destination. The CopyStreamException
* will contain the number of bytes confirmed to have been
* transferred before an
* IOException occurred, and it will also contain the IOException
* that caused the error. These values can be retrieved with
* the CopyStreamException getTotalBytesTransferred() and
* getIOException() methods.
***/
public static final long copyReader(Reader source, Writer dest,
int bufferSize, long streamSize,
CopyStreamListener listener)
throws CopyStreamException
{
int chars;
long total;
char[] buffer;
buffer = new char[bufferSize];
total = 0;
try
{
while ((chars = source.read(buffer)) != -1)
{
// Technically, some read(char[]) methods may return 0 and we cannot
// accept that as an indication of EOF.
if (chars == 0)
{
chars = source.read();
if (chars < 0)
break;
dest.write(chars);
dest.flush();
++total;
if (listener != null)
listener.bytesTransferred(total, chars, streamSize);
continue;
}
dest.write(buffer, 0, chars);
dest.flush();
total += chars;
if (listener != null)
listener.bytesTransferred(total, chars, streamSize);
}
}
catch (IOException e)
{
throw new CopyStreamException("IOException caught while copying.",
total, e);
}
return total;
}
/***
* Copies the contents of a Reader to a Writer using a
* copy buffer of a given size. The contents of the Reader are
* read until its end is reached, but neither the source nor the
* destination are closed. You must do this yourself outside of the
* method call. The number of characters read/written is returned.
*
* @param source The source Reader.
* @param dest The destination writer.
* @param bufferSize The number of characters to buffer during the copy.
* @return The number of characters read/written in the copy operation.
* @exception CopyStreamException If an error occurs while reading from the
* source or writing to the destination. The CopyStreamException
* will contain the number of bytes confirmed to have been
* transferred before an
* IOException occurred, and it will also contain the IOException
* that caused the error. These values can be retrieved with
* the CopyStreamException getTotalBytesTransferred() and
* getIOException() methods.
***/
public static final long copyReader(Reader source, Writer dest,
int bufferSize)
throws CopyStreamException
{
return copyReader(source, dest, bufferSize,
CopyStreamEvent.UNKNOWN_STREAM_SIZE, null);
}
/***
* Same as copyReader(source, dest, DEFAULT_COPY_BUFFER_SIZE);
***/
public static final long copyReader(Reader source, Writer dest)
throws CopyStreamException
{
return copyReader(source, dest, DEFAULT_COPY_BUFFER_SIZE);
}
}
|