Util.java
/*
* 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.
*/
package org.apache.commons.net.io;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.net.Socket;
import org.apache.commons.net.util.NetConstants;
/**
* The Util class cannot be instantiated and stores short static convenience methods that are often quite useful.
*
*
* @see CopyStreamException
* @see CopyStreamListener
* @see CopyStreamAdapter
*/
public final class Util {
/**
* The default buffer size ({@value}) used by {@link #copyStream copyStream } and {@link #copyReader copyReader} and by the copyReader/copyStream methods if
* a zero or negative buffer size is supplied.
*/
public static final int DEFAULT_COPY_BUFFER_SIZE = 1024;
/**
* Closes the object quietly, catching rather than throwing IOException. Intended for use from finally blocks.
*
* @param closeable the object to close, may be {@code null}
* @since 3.0
*/
public static void closeQuietly(final Closeable closeable) {
if (closeable != null) {
try {
closeable.close();
} catch (final IOException e) {
// Ignored
}
}
}
/**
* Closes the socket quietly, catching rather than throwing IOException. Intended for use from finally blocks.
*
* @param socket the socket to close, may be {@code null}
* @since 3.0
*/
public static void closeQuietly(final Socket socket) {
if (socket != null) {
try {
socket.close();
} catch (final IOException e) {
// Ignored
}
}
}
/**
* Same as <code> copyReader(source, dest, DEFAULT_COPY_BUFFER_SIZE); </code>
*
* @param source where to copy from
* @param dest where to copy to
* @return number of bytes copied
* @throws CopyStreamException on error
*/
public static long copyReader(final Reader source, final Writer dest) throws CopyStreamException {
return copyReader(source, dest, DEFAULT_COPY_BUFFER_SIZE);
}
/**
* 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 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. A zero or negative value means to use {@link #DEFAULT_COPY_BUFFER_SIZE}.
* @return The number of characters read/written in the copy operation.
* @throws 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 long copyReader(final Reader source, final Writer dest, final int bufferSize) throws CopyStreamException {
return copyReader(source, dest, bufferSize, CopyStreamEvent.UNKNOWN_STREAM_SIZE, null);
}
/**
* 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.
* <p>
* 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
* 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. A zero or negative value means to use {@link #DEFAULT_COPY_BUFFER_SIZE}.
* @param streamSize The number of characters in the stream being copied. Should be set to CopyStreamEvent.UNKNOWN_STREAM_SIZE if unknown. Not currently
* used (though it is passed to {@link CopyStreamListener#bytesTransferred(long, int, long)}
* @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.
* @throws 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 long copyReader(final Reader source, final Writer dest, final int bufferSize, final long streamSize, final CopyStreamListener listener)
throws CopyStreamException {
int numChars;
long total = 0;
final char[] buffer = new char[bufferSize > 0 ? bufferSize : DEFAULT_COPY_BUFFER_SIZE];
try {
while ((numChars = source.read(buffer)) != NetConstants.EOS) {
// Technically, some read(char[]) methods may return 0, and we cannot
// accept that as an indication of EOF.
if (numChars == 0) {
final int singleChar = source.read();
if (singleChar < 0) {
break;
}
dest.write(singleChar);
dest.flush();
++total;
if (listener != null) {
listener.bytesTransferred(total, 1, streamSize);
}
continue;
}
dest.write(buffer, 0, numChars);
dest.flush();
total += numChars;
if (listener != null) {
listener.bytesTransferred(total, numChars, streamSize);
}
}
} catch (final IOException e) {
throw new CopyStreamException("IOException caught while copying.", total, e);
}
return total;
}
/**
* Same as <code> copyStream(source, dest, DEFAULT_COPY_BUFFER_SIZE); </code>
*
* @param source where to copy from
* @param dest where to copy to
* @return number of bytes copied
* @throws CopyStreamException on error
*/
public static long copyStream(final InputStream source, final OutputStream dest) throws CopyStreamException {
return copyStream(source, dest, DEFAULT_COPY_BUFFER_SIZE);
}
/**
* 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 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. A zero or negative value means to use {@link #DEFAULT_COPY_BUFFER_SIZE}.
* @return The number of bytes read/written in the copy operation.
* @throws 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 long copyStream(final InputStream source, final OutputStream dest, final int bufferSize) throws CopyStreamException {
return copyStream(source, dest, bufferSize, CopyStreamEvent.UNKNOWN_STREAM_SIZE, null);
}
/**
* 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.
* <p>
* 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 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. A zero or negative value means to use {@link #DEFAULT_COPY_BUFFER_SIZE}.
* @param streamSize The number of bytes in the stream being copied. Should be set to CopyStreamEvent.UNKNOWN_STREAM_SIZE if unknown. Not currently used
* (though it is passed to {@link CopyStreamListener#bytesTransferred(long, int, long)}
* @param listener The CopyStreamListener to notify of progress. If this parameter is null, notification is not attempted.
* @return number of bytes read/written
* @throws 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 long copyStream(final InputStream source, final OutputStream dest, final int bufferSize, final long streamSize,
final CopyStreamListener listener) throws CopyStreamException {
return copyStream(source, dest, bufferSize, streamSize, listener, true);
}
/**
* 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.
* <p>
* 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 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. A zero or negative value means to use {@link #DEFAULT_COPY_BUFFER_SIZE}.
* @param streamSize The number of bytes in the stream being copied. Should be set to CopyStreamEvent.UNKNOWN_STREAM_SIZE if unknown. Not currently used
* (though it is passed to {@link CopyStreamListener#bytesTransferred(long, int, long)}
* @param listener The CopyStreamListener to notify of progress. If this parameter is null, notification is not attempted.
* @param flush Whether to flush the output stream after every write. This is necessary for interactive sessions that rely on buffered streams. If you
* don't flush, the data will stay in the stream buffer.
* @return number of bytes read/written
* @throws 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 long copyStream(final InputStream source, final OutputStream dest, final int bufferSize, final long streamSize,
final CopyStreamListener listener, final boolean flush) throws CopyStreamException {
int numBytes;
long total = 0;
final byte[] buffer = new byte[bufferSize > 0 ? bufferSize : DEFAULT_COPY_BUFFER_SIZE];
try {
while ((numBytes = source.read(buffer)) != NetConstants.EOS) {
// Technically, some read(byte[]) methods may return 0, and we cannot
// accept that as an indication of EOF.
if (numBytes == 0) {
final int singleByte = source.read();
if (singleByte < 0) {
break;
}
dest.write(singleByte);
if (flush) {
dest.flush();
}
++total;
if (listener != null) {
listener.bytesTransferred(total, 1, streamSize);
}
continue;
}
dest.write(buffer, 0, numBytes);
if (flush) {
dest.flush();
}
total += numBytes;
if (listener != null) {
listener.bytesTransferred(total, numBytes, streamSize);
}
}
} catch (final IOException e) {
throw new CopyStreamException("IOException caught while copying.", total, e);
}
return total;
}
/** Cannot be instantiated. */
private Util() {
}
}