poi/src/java/org/apache/poi/util/LongField.java

254 lines
7.6 KiB
Java

/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache POI" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache POI", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.poi.util;
import org.apache.poi.util.LittleEndian.BufferUnderrunException;
import java.io.*;
/**
* representation of a long (16-bit) field at a fixed location within
* a byte array
*
* @author Marc Johnson (mjohnson at apache dot org
*/
public class LongField
implements FixedField
{
private long _value;
private final int _offset;
/**
* construct the LongField with its offset into its containing
* byte array
*
* @param offset of the field within its byte array
*
* @exception ArrayIndexOutOfBoundsException if offset is negative
*/
public LongField(final int offset)
throws ArrayIndexOutOfBoundsException
{
if (offset < 0)
{
throw new ArrayIndexOutOfBoundsException("Illegal offset: "
+ offset);
}
_offset = offset;
}
/**
* construct the LongField with its offset into its containing
* byte array and initialize its value
*
* @param offset of the field within its byte array
* @param value the initial value
*
* @exception ArrayIndexOutOfBoundsException if offset is negative
*/
public LongField(final int offset, final long value)
throws ArrayIndexOutOfBoundsException
{
this(offset);
set(value);
}
/**
* Construct the LongField with its offset into its containing
* byte array and initialize its value from its byte array
*
* @param offset of the field within its byte array
* @param data the byte array to read the value from
*
* @exception ArrayIndexOutOfBoundsException if the offset is not
* within the range of 0..(data.length - 1)
*/
public LongField(final int offset, final byte [] data)
throws ArrayIndexOutOfBoundsException
{
this(offset);
readFromBytes(data);
}
/**
* construct the LongField with its offset into its containing
* byte array, initialize its value, and write the value to a byte
* array
*
* @param offset of the field within its byte array
* @param value the initial value
* @param data the byte array to write the value to
*
* @exception ArrayIndexOutOfBoundsException if offset is negative
*/
public LongField(final int offset, final long value, final byte [] data)
throws ArrayIndexOutOfBoundsException
{
this(offset);
set(value, data);
}
/**
* get the LongField's current value
*
* @return current value
*/
public long get()
{
return _value;
}
/**
* set the LongField's current value
*
* @param value to be set
*/
public void set(final long value)
{
_value = value;
}
/**
* set the LongField's current value and write it to a byte array
*
* @param value to be set
* @param data the byte array to write the value to
*
* @exception ArrayIndexOutOfBoundsException if the offset is out
* of range
*/
public void set(final long value, final byte [] data)
throws ArrayIndexOutOfBoundsException
{
_value = value;
writeToBytes(data);
}
/* ********** START implementation of FixedField ********** */
/**
* set the value from its offset into an array of bytes
*
* @param data the byte array from which the value is to be read
*
* @exception ArrayIndexOutOfBoundsException if the offset is out
* of range
*/
public void readFromBytes(final byte [] data)
throws ArrayIndexOutOfBoundsException
{
_value = LittleEndian.getLong(data, _offset);
}
/**
* set the value from an InputStream
*
* @param stream the InputStream from which the value is to be
* read
*
* @exception BufferUnderrunException if there is not enough data
* available from the InputStream
* @exception IOException if an IOException is thrown from reading
* the InputStream
*/
public void readFromStream(final InputStream stream)
throws IOException, BufferUnderrunException
{
_value = LittleEndian.readLong(stream);
}
/**
* write the value out to an array of bytes at the appropriate
* offset
*
* @param data the array of bytes to which the value is to be
* written
*
* @exception ArrayIndexOutOfBoundsException if the offset is out
* of range
*/
public void writeToBytes(final byte [] data)
throws ArrayIndexOutOfBoundsException
{
LittleEndian.putLong(data, _offset, _value);
}
/**
* return the value as a String
*
* @return the value as a String
*/
public String toString()
{
return String.valueOf(_value);
}
/* ********** END implementation of FixedField ********** */
} // end public class LongField