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JExcelApi is a java library which provides the ability to read, write, and modify Microsoft Excel spreadsheets.
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/*********************************************************************
*
* Copyright (C) 2002 Andrew Khan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***************************************************************************/
package jxl.write.biff;
import java.util.ArrayList;
import java.util.Iterator;
import jxl.biff.IntegerHelper;
import jxl.biff.StringHelper;
import jxl.biff.Type;
import jxl.biff.WritableRecordData;
/**
* A shared string table record.
*/
class SSTRecord extends WritableRecordData
{
/**
* The number of string references in the workbook
*/
private int numReferences;
/**
* The number of strings in this table
*/
private int numStrings;
/**
* The list of strings
*/
private ArrayList strings;
/**
* The list of string lengths
*/
private ArrayList stringLengths;
/**
* The binary data
*/
private byte[] data;
/**
* The count of bytes needed so far to contain this record
*/
private int byteCount;
/**
* The maximum amount of bytes available for the SST record
*/
private static int maxBytes = 8228 - // max length
8 - // bytes for string count fields
4; // standard biff record header
/**
* Constructor
*
* @param numRefs the number of string references in the workbook
* @param s the number of strings
*/
public SSTRecord(int numRefs, int s)
{
super(Type.SST);
numReferences = numRefs;
numStrings = s;
byteCount = 0;
strings = new ArrayList(50);
stringLengths = new ArrayList(50);
}
/**
* Adds a string to this SST record. It returns the number of string
* characters not added, due to space constraints. In the event
* of this being non-zero, a continue record will be needed
*
* @param s the string to add
* @return the number of characters not added
*/
public int add(String s)
{
int bytes = s.length() * 2 + 3;
// Must be able to add at least the first character of the string
// onto the SST
if (byteCount >= maxBytes - 5)
{
return s.length() > 0 ? s.length() : -1; // need to return some non-zero
// value in order to force the creation of a continue record
}
stringLengths.add(new Integer(s.length()));
if (bytes + byteCount < maxBytes)
{
// add the string and return
strings.add(s);
byteCount += bytes;
return 0;
}
// Calculate the number of characters we can add
int bytesLeft = maxBytes - 3 - byteCount;
int charsAvailable = bytesLeft % 2 == 0 ? bytesLeft / 2 :
(bytesLeft - 1) / 2;
// Add what strings we can
strings.add(s.substring(0, charsAvailable));
byteCount += charsAvailable * 2 + 3;
return s.length() - charsAvailable;
}
/**
* Gets the current offset into this record, excluding the header fields
*
* @return the number of bytes after the header field
*/
public int getOffset()
{
return byteCount + 8;
}
/**
* Gets the binary data for output to file
*
* @return the binary data
*/
public byte[] getData()
{
data = new byte[byteCount+8];
IntegerHelper.getFourBytes(numReferences, data, 0);
IntegerHelper.getFourBytes(numStrings, data, 4);
int pos = 8;
int count = 0;
Iterator i = strings.iterator();
String s = null;
int length = 0;
while (i.hasNext())
{
s = (String) i.next();
length = ( (Integer) stringLengths.get(count)).intValue();
IntegerHelper.getTwoBytes(length, data, pos);
data[pos+2] = 0x01;
StringHelper.getUnicodeBytes(s, data, pos+3);
pos += s.length() * 2 + 3;
count++;
}
return data;
}
}