How to Resolve java.io.EOFException: Unexpected End of ZLIB Input Stream in Apache POI?

What does the java.io.EOFException: Unexpected end of ZLIB input stream error mean in Apache POI?

The `java.io.EOFException: Unexpected end of ZLIB input stream` error typically occurs when dealing with compressed data streams in Java, especially while working with the Apache POI library that manipulates Microsoft Office documents. This exception indicates that the data stream is prematurely closed or corrupted, leading to issues when attempting to read through the ZLIB compression.

try (InputStream is = new FileInputStream("path/to/your/file.xlsx");\n    Workbook workbook = WorkbookFactory.create(is)) {\n    // Your code here to manipulate the workbook\n} catch (IOException e) {\n    e.printStackTrace();\n} catch (InvalidFormatException e) {\n    // Handle invalid format exceptions here\n}

Causes

• The input stream is not fully read or is truncated.
• Improper handling of streams when reading or writing files.
• Issues with file integrity, such as transfer errors or incomplete downloads.
• Using an incorrect format or corrupted Excel file with Apache POI.

Solutions

• Ensure the source file you are trying to read is complete and not corrupted.
• When reading files, use a proper method to handle streams, ensuring they are fully consumed before closing them.
• Check if you are correctly configuring the InputStream and OutputStream if you are dealing with compression directly.
• If downloading files over the network, verify the download is complete and check its integrity.

Mistake: Not closing streams properly, leading to resource leaks.

Solution: Always use try-with-resources or ensure that streams are closed in a finally block.

Mistake: Attempting to read or write to a null InputStream or OutputStream.

Solution: Check your stream initialization before usage to avoid null pointer exceptions.

Mistake: Using a corrupted or incomplete file format.

Solution: Validate that the Excel file is not corrupted and is fully downloaded.