Bug 65683

Can you attach a sample workbook and some code for a reproducible test-case which shows your case and allows others to try to help?

Created attachment 38095 [details]
this is origin excel template

Created attachment 38096 [details]
this is extract whole sheet named "attachment1 [details]" file from the origin excel

this is test case.

```
@Test
    public void testExtractSheet() throws IOException {
        Workbook workbook = WorkbookFactory.create(new File("template - 副本.xls"));
        try {
            int numberOfSheets = workbook.getNumberOfSheets();
            boolean found = false;
            String sheetNameToExtract = "attachment1 [details]";

            for (int i = 0; i < numberOfSheets; i++) {
                Sheet sheetAt = workbook.getSheetAt(i);
                if (!sheetAt.getSheetName().equalsIgnoreCase(sheetNameToExtract)) {
                    workbook.removeSheetAt(i--);
                    numberOfSheets--;
                } else {
                    found = true;
                }
            }
            if (!found) {
                workbook.close();
                throw new FileNotFoundException("can not find sheet: " + sheetNameToExtract);
            }
            File outputFile = new File(System.currentTimeMillis() + ".xls");
            FileUtils.createParentDirectories(outputFile);
            try (FileOutputStream stream = new FileOutputStream(outputFile)) {
                workbook.write(stream);
            }
        } finally {
            org.apache.commons.io.IOUtils.closeQuietly(workbook);
        }
    }
```

The result is that the original excel file is 847K and the sheet named "attachment1 [details]" contains only a simple excel, but when it is extracted to a new file, the new file size is 845K, so I guess poi will not delete the irrelevant files from this sheet.

Maybe you could write custom code to remove the attachments yourself. https://github.com/apache/poi/blob/trunk/poi/src/main/java/org/apache/poi/ss/extractor/EmbeddedExtractor.java will give you an idea how to iterate over the attachments.