Java Faker VS fastexcel

Faker was originally written in Perl and is also available as a library for Ruby, Java, and Python.

you can use faker java

JavaFaker for generating random data https://github.com/DiUS/java-faker

I've been using https://github.com/DiUS/java-faker which seems to be much more popular. How is this one different?

I'm using 1.0.2 from this repository: https://github.com/DiUS/java-faker

I'm Java developer. While we have had our fair share of shenanigans, if the people behind the Java equivalent of faker (https://github.com/DiUS/java-faker) went off the rails it wouldn't be anywhere near as much of an issue.

This has another bottleneck, each time you request something, it ends up with a IO call to open a file, as all fake data is stored in a file: https://github.com/datafaker-net/datafaker/blob/master/src/main/resources/en/dragon_ball.yml I recently filed a bug to javafaker that in some cases file descriptor was never closed, resulting in even worse performance and memory leaks, killing our service after millions of method calls.

I'm using fastexcel to create the excel file, and I'm flushing it to the OutputStream after every row is written. Right now, I am using a FileOutputStream to write to disk. When the excel file is done being generated, I read it back in using InputStreamResource and stream the response. My thought process is that a ByteArrayOutputStream keeps everything in memory even if I'm flushing the excel file after every row, so I used the FileOutputStream. Does my logic track here? Or am I unnecessarily slowing things down with expensive filesystem IO?

fastexcel the fastest xlsx generation library

I would use some library like for example this one. So you collect all the data you want to store in a list or map, and iterate over it, then add them to the excel like shown in the documentation of the library (should always be the same way more or less for any library)

I've only had memory problems with apache poi. I only use https://github.com/dhatim/fastexcel now