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The UnboundID LDAP SDK for Java is a fast, comprehensive, and easy-to-use
Java API for communicating with LDAP directory servers and performing
related tasks like reading and writing LDIF, encoding and decoding data
using base64 and ASN.1 BER, and performing secure communication. This
package contains the Standard Edition of the LDAP SDK, which is a
complete, general-purpose library for communicating with LDAPv3 directory
servers.
/*
* Copyright 2011-2022 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright 2011-2022 Ping Identity Corporation
*
* 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.
*/
/*
* Copyright (C) 2011-2022 Ping Identity Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (GPLv2 only)
* or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
* as published by the Free Software Foundation.
*
* This program 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*/
package com.unboundid.util;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import static com.unboundid.util.UtilityMessages.*;
/**
* This class provides an input stream implementation that can aggregate
* multiple input streams. When reading data from this input stream, it will
* read from the first input stream until the end of it is reached, at point it
* will close it and start reading from the next one, and so on until all input
* streams have been exhausted. Closing the aggregate input stream will cause
* all remaining input streams to be closed.
*/
@ThreadSafety(level=ThreadSafetyLevel.NOT_THREADSAFE)
public final class AggregateInputStream
extends InputStream
{
// The currently-active input stream.
@Nullable private volatile InputStream activeInputStream;
// The iterator that will be used to access the input streams.
@NotNull private final Iterator streamIterator;
/**
* Creates a new aggregate input stream that will use the provided set of
* input streams.
*
* @param inputStreams The input streams to be used by this aggregate input
* stream. It must not be {@code null}.
*/
public AggregateInputStream(@NotNull final InputStream... inputStreams)
{
this(StaticUtils.toList(inputStreams));
}
/**
* Creates a new aggregate input stream that will use the provided set of
* input streams.
*
* @param inputStreams The input streams to be used by this aggregate input
* stream. It must not be {@code null}.
*/
public AggregateInputStream(
@NotNull final Collection inputStreams)
{
Validator.ensureNotNull(inputStreams);
final ArrayList streamList = new ArrayList<>(inputStreams);
streamIterator = streamList.iterator();
activeInputStream = null;
}
/**
* Creates a new aggregate input stream that will read data from the specified
* files.
*
* @param files The set of files to be read by this aggregate input stream.
* It must not be {@code null}.
*
* @throws IOException If a problem is encountered while attempting to
* create input streams for the provided files.
*/
public AggregateInputStream(@NotNull final File... files)
throws IOException
{
this(false, files);
}
/**
* Creates a new aggregate input stream that will read data from the specified
* files.
*
* @param ensureBlankLinesBetweenFiles Indicates whether to ensure that
* there is at least one completely
* blank line between files. This may
* be useful when blank lines are
* used as delimiters (for example, when
* reading LDIF data), there is a chance
* that the files may not end with blank
* lines, and the inclusion of extra
* blank lines between files will not
* cause any harm.
* @param files The set of files to be read by this
* aggregate input stream. It must not
* be {@code null}.
*
* @throws IOException If a problem is encountered while attempting to
* create input streams for the provided files.
*/
public AggregateInputStream(final boolean ensureBlankLinesBetweenFiles,
@NotNull final File... files)
throws IOException
{
Validator.ensureNotNull(files);
final ArrayList streamList = new ArrayList<>(2 * files.length);
IOException ioException = null;
for (final File f : files)
{
if (ensureBlankLinesBetweenFiles && (! streamList.isEmpty()))
{
final ByteStringBuffer buffer = new ByteStringBuffer(4);
buffer.append(StaticUtils.EOL_BYTES);
buffer.append(StaticUtils.EOL_BYTES);
streamList.add(new ByteArrayInputStream(buffer.toByteArray()));
}
try
{
streamList.add(new FileInputStream(f));
}
catch (final IOException ioe)
{
Debug.debugException(ioe);
ioException = ioe;
break;
}
}
if (ioException != null)
{
for (final InputStream s : streamList)
{
if (s != null)
{
try
{
s.close();
}
catch (final Exception e)
{
Debug.debugException(e);
}
}
}
throw ioException;
}
streamIterator = streamList.iterator();
activeInputStream = null;
}
/**
* Reads the next byte of data from the current active input stream, switching
* to the next input stream in the set if appropriate.
*
* @return The next byte of data that was read, or -1 if all streams have
* been exhausted.
*
* @throws IOException If a problem is encountered while attempting to read
* data from an input stream.
*/
@Override()
public int read()
throws IOException
{
while (true)
{
if (activeInputStream == null)
{
if (streamIterator.hasNext())
{
activeInputStream = streamIterator.next();
continue;
}
else
{
return -1;
}
}
final int byteRead = activeInputStream.read();
if (byteRead < 0)
{
activeInputStream.close();
activeInputStream = null;
}
else
{
return byteRead;
}
}
}
/**
* Reads data from the current active input stream into the provided array,
* switching to the next input stream in the set if appropriate.
*
* @param b The array into which the data read should be placed, starting
* with an index of zero. It must not be {@code null}.
*
* @return The number of bytes read into the array, or -1 if all streams have
* been exhausted.
*
* @throws IOException If a problem is encountered while attempting to read
* data from an input stream.
*/
@Override()
public int read(@NotNull final byte[] b)
throws IOException
{
return read(b, 0, b.length);
}
/**
* Reads data from the current active input stream into the provided array,
* switching to the next input stream in the set if appropriate.
*
* @param b The array into which the data read should be placed. It must
* not be {@code null}.
* @param off The position in the array at which to start writing data.
* @param len The maximum number of bytes that may be read.
*
* @return The number of bytes read into the array, or -1 if all streams have
* been exhausted.
*
* @throws IOException If a problem is encountered while attempting to read
* data from an input stream.
*/
@Override()
public int read(@NotNull final byte[] b, final int off, final int len)
throws IOException
{
while (true)
{
if (activeInputStream == null)
{
if (streamIterator.hasNext())
{
activeInputStream = streamIterator.next();
continue;
}
else
{
return -1;
}
}
final int bytesRead = activeInputStream.read(b, off, len);
if (bytesRead < 0)
{
activeInputStream.close();
activeInputStream = null;
}
else
{
return bytesRead;
}
}
}
/**
* Attempts to skip and discard up to the specified number of bytes from the
* input stream.
*
* @param n The number of bytes to attempt to skip.
*
* @return The number of bytes actually skipped.
*
* @throws IOException If a problem is encountered while attempting to skip
* data from the input stream.
*/
@Override()
public long skip(final long n)
throws IOException
{
if (activeInputStream == null)
{
if (streamIterator.hasNext())
{
activeInputStream = streamIterator.next();
return activeInputStream.skip(n);
}
else
{
return 0L;
}
}
else
{
return activeInputStream.skip(n);
}
}
/**
* Retrieves an estimate of the number of bytes that can be read without
* blocking.
*
* @return An estimate of the number of bytes that can be read without
* blocking.
*
* @throws IOException If a problem is encountered while attempting to make
* the determination.
*/
@Override()
public int available()
throws IOException
{
if (activeInputStream == null)
{
if (streamIterator.hasNext())
{
activeInputStream = streamIterator.next();
return activeInputStream.available();
}
else
{
return 0;
}
}
else
{
return activeInputStream.available();
}
}
/**
* Indicates whether this input stream supports the use of the {@code mark}
* and {@code reset} methods. This implementation does not support that
* capability.
*
* @return {@code false} to indicate that this input stream implementation
* does not support the use of {@code mark} and {@code reset}.
*/
@Override()
public boolean markSupported()
{
return false;
}
/**
* Marks the current position in the input stream. This input stream does not
* support this functionality, so no action will be taken.
*
* @param readLimit The maximum number of bytes that the caller may wish to
* read before being able to reset the stream.
*/
@Override()
public void mark(final int readLimit)
{
// No implementation is required.
}
/**
* Attempts to reset the position of this input stream to the mark location.
* This implementation does not support {@code mark} and {@code reset}
* functionality, so this method will always throw an exception.
*
* @throws IOException To indicate that reset is not supported.
*/
@Override()
public void reset()
throws IOException
{
throw new IOException(ERR_AGGREGATE_INPUT_STREAM_MARK_NOT_SUPPORTED.get());
}
/**
* Closes this input stream. All associated input streams will be closed.
*
* @throws IOException If an exception was encountered while attempting to
* close any of the associated streams. Note that even
* if an exception is encountered, an attempt will be
* made to close all streams.
*/
@Override()
public void close()
throws IOException
{
IOException firstException = null;
if (activeInputStream != null)
{
try
{
activeInputStream.close();
}
catch (final IOException ioe)
{
Debug.debugException(ioe);
firstException = ioe;
}
activeInputStream = null;
}
while (streamIterator.hasNext())
{
final InputStream s = streamIterator.next();
try
{
s.close();
}
catch (final IOException ioe)
{
Debug.debugException(ioe);
if (firstException == null)
{
firstException = ioe;
}
}
}
if (firstException != null)
{
throw firstException;
}
}
}