Use Aspose.Words for Java to range-split a 1243-page document and select pages 0-1000. After splitting the document, the document is 988 pages.
@xingyu11 Could you please attach your input document here for testing? We will check the issue and provide you more information.
You should note that MS Word documents are flow by their nature and does not have “page” concept. The consumer applications reflows the document content into pages on the fly. So to extract pages from the document Aspose.Words also builds the document layout. The problem on your side might occur because the fonts used in your input document are not available on the machine where document is processed. The fonts are required to build document layout. If Aspose.Words cannot find the font used in the document, the font is substituted. This might lead into fonts mismatch and document layout differences due to the different fonts metrics and as a result incorrect page detection. You can implement IWarningCallback to get notifications when font substitution is performed.
Please see our documentation to learn where Aspose.Words looks for fonts:
https://docs.aspose.com/words/net/specifying-truetype-fonts-location/