com.unboundid.util.FixedArrayOutputStream Maven / Gradle / Ivy
/*
* Copyright 2010-2021 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright 2010-2021 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) 2010-2021 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.IOException;
import java.io.OutputStream;
import java.io.Serializable;
import static com.unboundid.util.UtilityMessages.*;
/**
* This class provides an {@code OutputStream} implementation that writes data
* to a provided byte array. It is similar to the
* {@code java.io.ByteArrayOutputStream} class, except that it allows you to
* pass in the array that it uses, and the array will not grow over time.
*/
@Mutable()
@ThreadSafety(level=ThreadSafetyLevel.NOT_THREADSAFE)
public final class FixedArrayOutputStream
extends OutputStream
implements Serializable
{
/**
* The serial version UID for this serializable class.
*/
private static final long serialVersionUID = 4678108653480347534L;
// The byte array used by this class.
@NotNull private final byte[] array;
// The initial position for this array.
private final int initialPosition;
// The maximum number of bytes that may be written.
private final int length;
// The maximum position at which data may be written.
private final int maxPosition;
// The current position at which data may be written.
private int pos;
/**
* Creates a new output stream that will write data to the provided array.
* It will use the entire array.
*
* @param array The array to which data will be written. It must not be
* {@code null}.
*/
public FixedArrayOutputStream(@NotNull final byte[] array)
{
this(array, 0, array.length);
}
/**
* Creates a new output stream that will write data to the provided array.
* It will use the specified portion of the array.
*
* @param array The array to which data will be written. It must not be
* {@code null}.
* @param pos The position at which to start writing data. It must be
* greater than or equal to zero and less than or equal to the
* length of the array.
* @param len The maximum number of bytes that may be written. It must
* be greater than or equal to zero and less than or equal to
* the difference between the length of the array and the
* provided {@code pos} value.
*/
public FixedArrayOutputStream(@NotNull final byte[] array, final int pos,
final int len)
{
this.array = array;
this.pos = pos;
initialPosition = pos;
maxPosition = pos + len;
length = len;
Validator.ensureTrue((pos >= 0),
"The position must be greater than or equal to zero.");
Validator.ensureTrue((len >= 0),
"The length must be greater than or equal to zero.");
Validator.ensureTrue((maxPosition <= array.length),
"The sum of pos and len must not exceed the array length.");
}
/**
* Retrieves the backing array used by this output stream.
*
* @return The backing array used by this output stream.
*/
@NotNull()
public byte[] getBackingArray()
{
return array;
}
/**
* Retrieves the initial position provided when this output stream was
* created.
*
* @return The initial position provided when this output stream was created.
*/
public int getInitialPosition()
{
return initialPosition;
}
/**
* Retrieves the maximum number of bytes that may be written to this output
* stream.
*
* @return The maximum number of bytes that may be written to this output
* stream.
*/
public int getLength()
{
return length;
}
/**
* Retrieves the number of bytes that have been written so far to this output
* stream.
*
* @return The number of bytes that have been written so far to this output
* stream.
*/
public int getBytesWritten()
{
return (pos - initialPosition);
}
/**
* Closes this output stream. This has no effect.
*/
@Override()
public void close()
{
// No implementation required.
}
/**
* Flushes this output stream. This has no effect.
*/
@Override()
public void flush()
{
// No implementation required.
}
/**
* Writes the provided byte to this output stream.
*
* @param b The byte to be written.
*
* @throws IOException If an attempt was made to write beyond the end of the
* array.
*/
@Override()
public void write(final int b)
throws IOException
{
if (pos >= maxPosition)
{
throw new IOException(ERR_FIXED_ARRAY_OS_WRITE_BEYOND_END.get());
}
array[pos++] = (byte) b;
}
/**
* Writes the contents of the provided array to this output stream.
*
* @param b The byte array containing the data to be written. It must not
* be {@code null}.
*
* @throws IOException If an attempt was made to write beyond the end of the
* array.
*/
@Override()
public void write(@NotNull final byte[] b)
throws IOException
{
write(b, 0, b.length);
}
/**
* Writes the contents of the provided array to this output stream.
*
* @param b The byte array containing the data to be written. It must not
* be {@code null}.
* @param off The offset within the provided array of the beginning of the
* data to be written. It must be greater than or equal to zero
* and less than or equal to the length of the provided array.
* @param len The number of bytes to be written. It must be greater than or
* equal to zero, and the sum of {@code off} and {@code len} must
* be less than the length of the provided array.
*
* @throws IOException If an attempt was made to write beyond the end of the
* array.
*/
@Override()
public void write(@NotNull final byte[] b, final int off, final int len)
throws IOException
{
Validator.ensureTrue((off >= 0),
"The provided offset must be greater than or equal to zero.");
Validator.ensureTrue((len >= 0),
"The provided length must be greater than or equal to zero.");
Validator.ensureTrue(((off + len) <= b.length),
"The sum of off and len must not exceed the array length.");
if ((pos + len) > maxPosition)
{
throw new IOException(ERR_FIXED_ARRAY_OS_WRITE_BEYOND_END.get());
}
System.arraycopy(b, off, array, pos, len);
pos += len;
}
}