Find Java files with no declared constructors

java-files-with-no-declared-constructors.sh

# These two commands both search the working directory
# for java class files that do not declare a constructor.
#
# The first command is marginally faster than the second;
# for truly large code bases, this may matter,
# but mostly it won't.
#
# The commands disregard package-info.java and tests.

# #1: Finds all files in the first pass,
# then greps them in a second pass.
for file in $(find . -type f -name '*.java' | grep -v 'Test\|package-info'); do
    class="${file##*/}" && class="${class%*.java}"
    echo "$(grep --count "\( \|private\|protected\|public\) $class(" "$file") $file";
done | grep '^0'

# #2: Finds and greps files in the same pass.
find . -type f -name '*.java' \
    -a -not -iname 'package-info.java' \
    -a -not -iname '*test*' \
    -exec sh -c 'for file; do
    class="${file##*/}" && class="${class%*.java}"
    echo "$(grep --count "\( \|private\|protected\|public\) $class(" "$file") $file"
done' _ {} + | grep '^0'

# For both methods,
# the constructor examination can be moved into a function.
# This method is never faster than #2.
# NB: this worked for -exec bash but not -exec sh.

# Derives the Java class name from a Java file path.
ctors_in_file()
{
    file=$1
    class="${file##*/}" && class="${class%*.java}"
    echo "$(grep --count "\( \|private\|protected\|public\) $class(" "$file") $file";
}
export -f ctors_in_file

find . -type f -name '*.java' \
    -a -not -iname 'package-info.java' \
    -a -not -iname '*test*' \
    -exec bash -c 'for file; do ctors_in_file $file; done' _ {} + | grep '^0'