Question

I need to write a Git pre commit hook in Java, which would check if the code commited by the developer is formatted according to a specific eclipse code formatter before actually commiting it, otherwise reject it from commiting. Is it possible to write the pre commit hook in Java?

Answer 1

The idea is to call a script which in turns call your java program (checking the format).

You can see here an example written in python, which calls java.

try:
    # call checkstyle and print output
    print call(['java', '-jar', checkstyle, '-c', checkstyle_config, '-r', tempdir])
except subprocess.CalledProcessError, ex:
    print ex.output  # print checkstyle messages
    exit(1)
finally:
    # remove temporary directory
    shutil.rmtree(tempdir)

This other example calls directly ant, in order to execute an ant script (which in turns call a Java JUnit test suite)

#!/bin/sh

# Run the test suite.
# It will exit with 0 if it everything compiled and tested fine.
ant test
if [ $? -eq 0 ]; then
  exit 0
else
  echo "Building your project or running the tests failed."
  echo "Aborting the commit. Run with --no-verify to ignore."
  exit 1
fi