Unable to read entire header; 0 bytes read; expected 512 bytes

Question

I am using Apache poi 3.8 for reading xls file, but i got exception:

        java.io.IOException: Unable to read entire header; 0 bytes read; expected 512 bytes
        at org.apache.poi.poifs.storage.HeaderBlock.alertShortRead(HeaderBlock.java:226)
        at org.apache.poi.poifs.storage.HeaderBlock.readFirst512(HeaderBlock.java:207)
        at org.apache.poi.poifs.storage.HeaderBlock.<init>(HeaderBlock.java:104)
        at org.apache.poi.poifs.filesystem.POIFSFileSystem.<init>(POIFSFileSystem.java:138)

used code sample:

     FileInputStream myInput = new FileInputStream(excelFilePathWithExtension);
     logger.debug("FileInputStream::"+myInput);

     POIFSFileSystem myFileSystem = new POIFSFileSystem(myInput);
     logger.debug("POIFSFileSystem::"+myFileSystem);

     Workbook workbook = WorkbookFactory.create(myFileSystem);

please help me?

can you open file in excel or openOffice? if not then file is corrupted — Nandkumar Tekale, Sep 27 '12 at 08:04
If the excel file is empty, this way we should not read the file? What would be the correct way to check empty excel file? — Harleen, Mar 01 '16 at 06:05

score 7 · Accepted Answer · answered Sep 27 '12 at 08:49

If we take a look at the HeaderBlocks class, we can see these blocks :

public HeaderBlock(InputStream stream) throws IOException {
    // Grab the first 512 bytes
    // (For 4096 sized blocks, the remaining 3584 bytes are zero)
    // Then, process the contents
    this(readFirst512(stream));
    ...
}

The constructor you used will read the first 512 bytes of your inputstream then call a private constructor.

And the readFirst512 method throw an exception if there is not enough bytes to read.

Also, the POI's document say that a POI file system structure starts starts with a header block of 512 bytes.

So... It seems that your file is not big enough for POI.

I have the same problem but the file is 1,536 bytes... Any idea on how to solve this? — softwareplay, Oct 28 '14 at 16:55

score 3 · Answer 2 · edited Nov 04 '12 at 14:14

3

Open in MS-Excel and save as different name. Try again.

edited Nov 04 '12 at 14:14

Abdul Rahman

2,097
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answered Nov 04 '12 at 13:46

kfatih

119
1
5

Even opening the file, doing a minor edit and saving works. In my case I edited one cell, saved then undo the changes, saved again and the exception was gone. Because it is a template file probably it got corrupted along the way. Excel can fix the problem POI crashes. Programmatically I will adapt my code to first copy the template file to a temporary directory and then do any operations. – Louis Papaloizou Jun 12 '17 at 15:09

score 0 · Answer 3 · answered Aug 12 '16 at 12:21

0

if you place the files being read or written in different folder you may not get the error. Some default folders like 'Downloads' of Mozilla have restricted permissions, it seems.

answered Aug 12 '16 at 12:21

ravi

1

score 0 · Answer 4 · answered Dec 05 '22 at 09:13

0

I also faced same problem even though the my excel file containing data. After upgrading my POI jar file version to poi-3.9.jar my issue resolved. Hope this will be helpful.

answered Dec 05 '22 at 09:13

rajkumar chilukuri

235
1
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Unable to read entire header; 0 bytes read; expected 512 bytes

4 Answers4