When uploading and processing a large .xls
file through Java in an AEM backend, I encountered the following exception:
Stack Trace:
Explanation of the Issue
This exception occurs because Apache POI tries to allocate a large byte array to process the Excel file, exceeding the default size limit of 100,000,000 bytes. The issue is often due to the size or structure of the .xls
file, which requires a larger array than Apache POI allows by default.
Solutions
There are two primary ways to resolve this issue:
Option 1: Increase the Byte Array Limit
You can override the maximum allowable byte array size using IOUtils.setByteArrayMaxOverride()
. Setting this to a higher value, such as 200,000,000
, may help process larger Excel files. However, this approach can impact memory usage and may lead to performance issues with very large files. Before increasing the size, make sure the issue isn’t due to a corrupted or incorrect file format.
Updated Code Snippet:
Command to Compile and Run:
javac -cp ".;poi-5.3.0.jar;poi-ooxml-5.3.0.jar;poi-ooxml-full-5.3.0.jar;poi-ooxml-schemas-5.3.0.jar;xmlbeans-5.1.1.jar;commons-collections4-4.5.0-M2.jar;commons-io-2.17.0.jar;log4j-api-2.24.1.jar;commons-compress-1.27.1.jar;log4j-core-2.24.1.jar" ExcelReader.java
java -cp ".;poi-5.3.0.jar;poi-ooxml-5.3.0.jar;poi-ooxml-full-5.3.0.jar;poi-ooxml-schemas-5.3.0.jar;xmlbeans-5.1.1.jar;commons-collections4-4.5.0-M2.jar;commons-io-2.17.0.jar;log4j-api-2.24.1.jar;commons-compress-1.27.1.jar;log4j-core-2.24.1.jar" ExcelReader
Option 2: Use the Streaming API (SXSSFWorkbook)
Using SXSSFWorkbook, a streaming API in Apache POI, allows you to process large .xlsx
files in a memory-efficient way. This approach loads only a small part of the file into memory at any time, making it suitable for processing large Excel files.
Code Using SXSSFWorkbook:
Command to Compile and Run:
Conclusion
- Option 1: Increasing the byte array limit using
IOUtils.setByteArrayMaxOverride()
can solve the immediate issue but may impact memory usage. - Option 2: Using
SXSSFWorkbook
with the streaming API is a more scalable solution for large.xlsx
files, allowing memory-efficient processing.
Choose the approach that best suits your file size and memory requirements. Let me know if you have any questions!