Suggested fix for Illegal length exception when trying to read Excel sheet

[Neil Aggarwal <ne...@JAMMConsulting.com>]

Hello all:

I traced through the POI source code.

The problem is happening when fillFields(RecordInputStream in)
calls this line:

field_5_username = in.readCompressedUnicode(field_3_username_length);

RecordInputStream has this condition at the top of
readCompressedUnicode(int length)
    if ((length < 0) || ((remaining() < length) && !isContinueNext())) {
            throw new IllegalArgumentException("Illegal length");
    }

In this instance, length is zero, remaining() returns -1, and
isContinueNext() returns false.  That make the if statement fire
the exception.

If the length is zero, we should return an empty string.  So,
if I add this check to the top of the method:
    if( length <= 0 )
      return "";

Everything works fine.

I think this is a pretty simple patch so I added it to the
bugzilla:
https://issues.apache.org/bugzilla/show_bug.cgi?id=44643

Thanks,
  Neil


--
Neil Aggarwal, (832)245-7314, www.JAMMConsulting.com
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> -----Original Message-----
> From: Neil Aggarwal [mailto:neil@jammconsulting.com] 
> Sent: Wednesday, March 19, 2008 4:40 PM
> To: user@poi.apache.org
> Subject: Illegal length exception when trying to read Excel sheet
> 
> Hello:
> 
> This is really strange.  I have two empty spreadsheets.  POI 
> can read one
> but not the other.
> 
> When I try to read the sheet.xls file, I get this exception:
> 
> Exception in thread "main" 
> org.apache.poi.hssf.record.RecordFormatException:
> Unable to construct record instance
> 	at
> org.apache.poi.hssf.record.RecordFactory.createRecord(RecordFa
> ctory.java:199
> )
> 	at
> org.apache.poi.hssf.record.RecordFactory.createRecords(RecordF
> actory.java:11
> 7)
> 	at
> org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook
> .java:207)
> 	at
> org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook
> .java:259)
> 	at
> org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook
> .java:240)
> 	at POITest.main(POITest.java:9)
> Caused by: java.lang.reflect.InvocationTargetException
> 	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
> Method)
> 	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown
> Source)
> 	at 
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
> Source)
> 	at java.lang.reflect.Constructor.newInstance(Unknown Source)
> 	at
> org.apache.poi.hssf.record.RecordFactory.createRecord(RecordFa
> ctory.java:187
> )
> 	... 5 more
> Caused by: java.lang.IllegalArgumentException: Illegal length
> 	at
> org.apache.poi.hssf.record.RecordInputStream.readCompressedUni
> code(RecordInp
> utStream.java:270)
> 	at
> org.apache.poi.hssf.record.FileSharingRecord.fillFields(FileSh
> aringRecord.ja
> va:62)
> 	at org.apache.poi.hssf.record.Record.<init>(Record.java:55)
> 	at
> org.apache.poi.hssf.record.FileSharingRecord.<init>(FileSharin
> gRecord.java:4
> 8)
> 	... 10 more
> 
> Here is my code:
> 
> import java.io.*;
> import org.apache.poi.hssf.usermodel.HSSFWorkbook;
> 
> public class POITest {
>   public static void main(String[] args) throws Exception{
>     System.out.println("Reading sheet 2:");
>     new HSSFWorkbook(new FileInputStream("C:\\Tmp\\sheet2.xls"));
>     System.out.println("Reading sheet 1:");
>     new HSSFWorkbook(new FileInputStream("C:\\Tmp\\sheet.xls"));
>   }
> }
> 
> I have attached the spreadsheets.  
> 
> Any ideas what is happening?
> 
> Thanks,
> 	Neil
> 
> --
> Neil Aggarwal, (832)245-7314, www.JAMMConsulting.com
> Eliminate junk email and reclaim your inbox.
> Visit http://www.spammilter.com for details.
> 


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