configurePOI: Configuring Apache POI

In XLConnect: Excel Connector for R

Configuring Apache POI

Description

Configures Apache POI and related components.

Usage

configurePOI(zip_max_files = 1000L, zip_min_inflate_ratio = 0.001,
  zip_max_entry_size = 0xFFFFFFFF, zip_max_text_size = 10*1024*1024,
  zip_entry_threshold_bytes = -1L, max_size_byte_array = -1L,
  java_io_tmpdir = tempdir())

Arguments

zip_max_files	Integer scalar specifying the maximum number of files allowed inside an *.xlsx file. Defaults to 1000.
zip_min_inflate_ratio	Numeric scalar specifying the ratio between de- and inflated bytes to detect zip-bombs. If the compression ratio is better than the specified number an error will be thrown. Defaults to 0.001.
zip_max_entry_size	Integer scalar specifying the maximum file size of a single zip entry in an *.xlsx file. Defaults to 4'294'967'295 bytes, which is 4GB.
zip_max_text_size	Integer scalar specifying the maximum number of characters of text that are extracted before an error is thrown. Defaults to 10'485'760.
zip_entry_threshold_bytes	Integer scalar specifying the number of bytes at which a zip entry is regarded as too large for holding in memory and the data is put in a temp file instead. Defaults to -1L, meaning temp files are not used and that zip entries with more than 2GB of data after decompressing will fail. 0L means all zip entries are stored in temp files.
max_size_byte_array	Integer scalar specifying the maximum number of bytes that should be possible to be allocated in a single step. Increasing this limit can help if you are dealing with large Excel files, but note that this may demand a larger heap space (see option java.parameters; e.g. options(java.parameters = "-Xmx8192m"). Defaults to -1, which means that record-specific limits apply.)
java_io_tmpdir	Directory to hold POI temporary files and generally any temporary files produced by the Java subprocess. Defaults to the R session temporary directory tempdir()

Details

Many of the settings exposed here exist for security reasons to prevent excessive memory consumption and protect against security vulnerabilities when processing documents provided by untrusted sources.

Author(s)

Martin Studer
Mirai Solutions GmbH https://mirai-solutions.ch

References

Apache POI configuration: https://poi.apache.org/components/configuration.html

Examples

## Not run: 
configurePOI(zip_max_files = 5000L, max_size_byte_array = 250000000L)

## End(Not run)

XLConnect documentation built on June 8, 2025, 10:15 a.m.