org.apache.poi.util.IntegerField Maven / Gradle / Ivy
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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
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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,
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limitations under the License.
==================================================================== */
package org.apache.poi.util;
import org.apache.poi.util.LittleEndian.BufferUnderrunException;
import java.io.*;
/**
* representation of an integer (32-bit) field at a fixed location
* within a byte array
*
* @author Marc Johnson (mjohnson at apache dot org
*/
public class IntegerField
implements FixedField
{
private int _value;
private final int _offset;
/**
* construct the IntegerField with its offset into its containing
* byte array
*
* @param offset of the field within its byte array
*
* @exception ArrayIndexOutOfBoundsException if the offset is
* negative
*/
public IntegerField(final int offset)
throws ArrayIndexOutOfBoundsException
{
if (offset < 0)
{
throw new ArrayIndexOutOfBoundsException("negative offset");
}
_offset = offset;
}
/**
* construct the IntegerField 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 the offset is
* negative
*/
public IntegerField(final int offset, final int value)
throws ArrayIndexOutOfBoundsException
{
this(offset);
set(value);
}
/**
* Construct the IntegerField 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 IntegerField(final int offset, final byte [] data)
throws ArrayIndexOutOfBoundsException
{
this(offset);
readFromBytes(data);
}
/**
* construct the IntegerField 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 the offset is
* negative or too large
*/
public IntegerField(final int offset, final int value, final byte [] data)
throws ArrayIndexOutOfBoundsException
{
this(offset);
set(value, data);
}
/**
* get the IntegerField's current value
*
* @return current value
*/
public int get()
{
return _value;
}
/**
* set the IntegerField's current value
*
* @param value to be set
*/
public void set(final int value)
{
_value = value;
}
/**
* set the IntegerField'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 too
* large
*/
public void set(final int 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 too
* large
*/
public void readFromBytes(final byte [] data)
throws ArrayIndexOutOfBoundsException
{
_value = LittleEndian.getInt(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.readInt(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 too
* large
*/
public void writeToBytes(final byte [] data)
throws ArrayIndexOutOfBoundsException
{
LittleEndian.putInt(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 IntegerField